[trigger] Use trigger_xxx prefix for variable naming

Static variables do not have unique names and are shadowed by
function parameters even within this compilation module.

Make the code easier to follow by using common prefix for
module variables.
Signed-off-by: Simo Piiroinen <simo.piiroinen@jollamobile.com>

src/usb_moded-trigger.c

@@ -52,28 +52,27 @@
 
 /* -- trigger -- */
 
-static void     trigger_notify_issue         (gpointer data);
+static void     trigger_udev_error_cb        (gpointer data);
+static gboolean trigger_udev_input_cb        (GIOChannel *iochannel, GIOCondition cond, gpointer data);
+static void     trigger_parse_udev_properties(struct udev_device *dev);
 gboolean        trigger_init                 (void);
-static gboolean trigger_udev_event_cb        (GIOChannel *iochannel, GIOCondition cond, gpointer data);
 void            trigger_stop                 (void);
-static void     trigger_parse_udev_properties(struct udev_device *dev);
 
 /* ========================================================================= *
  * Data
  * ========================================================================= */
 
-/* global variables */
-static struct udev *udev = 0;
-static struct udev_monitor *mon = 0;
-static GIOChannel *iochannel = 0;
-static guint watch_id = 0;
-static const char *dev_name = 0;
+static struct udev         *trigger_udev_handle    = 0;
+static struct udev_monitor *trigger_udev_monitor   = 0;
+static GIOChannel          *trigger_udev_iochannel = 0;
+static guint                trigger_udev_input_id  = 0;
+static const char          *trigger_udev_sysname   = 0;
 
 /* ========================================================================= *
  * Functions
  * ========================================================================= */
 
-static void trigger_notify_issue (gpointer data)
+static void trigger_udev_error_cb (gpointer data)
 {
     (void)data;
 
@@ -90,8 +89,8 @@ gboolean trigger_init(void)
     int ret = 0;
 
     /* Create the udev object */
-    udev = udev_new();
-    if (!udev)
+    trigger_udev_handle = udev_new();
+    if (!trigger_udev_handle)
     {
         log_err("Can't create udev\n");
         return 1;
@@ -99,7 +98,7 @@ gboolean trigger_init(void)
 
     udev_path = config_check_trigger();
     if(udev_path)
-        dev = udev_device_new_from_syspath(udev, udev_path);
+        dev = udev_device_new_from_syspath(trigger_udev_handle, udev_path);
     else
     {
         log_err("No trigger path. Not starting trigger.\n");
@@ -112,23 +111,23 @@ gboolean trigger_init(void)
     }
     else
     {
-        dev_name = udev_device_get_sysname(dev);
-        log_debug("device name = %s\n", dev_name);
+        trigger_udev_sysname = udev_device_get_sysname(dev);
+        log_debug("device name = %s\n", trigger_udev_sysname);
     }
-    mon = udev_monitor_new_from_netlink (udev, "udev");
-    if (!mon)
+    trigger_udev_monitor = udev_monitor_new_from_netlink (trigger_udev_handle, "udev");
+    if (!trigger_udev_monitor)
     {
         log_err("Unable to monitor the netlink\n");
         /* communicate failure, mainloop will exit and call appropriate clean-up */
         return 1;
     }
-    ret = udev_monitor_filter_add_match_subsystem_devtype(mon, config_get_trigger_subsystem(), NULL);
+    ret = udev_monitor_filter_add_match_subsystem_devtype(trigger_udev_monitor, config_get_trigger_subsystem(), NULL);
     if(ret != 0)
     {
         log_err("Udev match failed.\n");
         return 1;
     }
-    ret = udev_monitor_enable_receiving (mon);
+    ret = udev_monitor_enable_receiving (trigger_udev_monitor);
     if(ret != 0)
     {
         log_err("Failed to enable monitor recieving.\n");
@@ -138,29 +137,29 @@ gboolean trigger_init(void)
     /* check if we are already connected */
     trigger_parse_udev_properties(dev);
 
-    iochannel = g_io_channel_unix_new(udev_monitor_get_fd(mon));
-    watch_id = g_io_add_watch_full(iochannel, 0, G_IO_IN, trigger_udev_event_cb, NULL, trigger_notify_issue);
+    trigger_udev_iochannel = g_io_channel_unix_new(udev_monitor_get_fd(trigger_udev_monitor));
+    trigger_udev_input_id = g_io_add_watch_full(trigger_udev_iochannel, 0, G_IO_IN, trigger_udev_input_cb, NULL, trigger_udev_error_cb);
 
     /* everything went well */
     log_debug("Trigger enabled!\n");
     return 0;
 }
 
-static gboolean trigger_udev_event_cb(GIOChannel *iochannel G_GNUC_UNUSED, GIOCondition cond,
-                                      gpointer data G_GNUC_UNUSED)
+static gboolean trigger_udev_input_cb(GIOChannel *iochannel G_GNUC_UNUSED, GIOCondition cond,
+                               gpointer data G_GNUC_UNUSED)
 {
     struct udev_device *dev;
 
     if(cond & G_IO_IN)
     {
         /* This normally blocks but G_IO_IN indicates that we can read */
-        dev = udev_monitor_receive_device (mon);
+        dev = udev_monitor_receive_device (trigger_udev_monitor);
         if (dev)
         {
             /* check if it is the actual device we want to check */
-            if(strcmp(dev_name, udev_device_get_sysname(dev))) {
+            if(strcmp(trigger_udev_sysname, udev_device_get_sysname(dev))) {
                 log_crit("name does not match, disabling udev trigger io-watch");
-                watch_id = 0;
+                trigger_udev_input_id = 0;
                 return FALSE;
             }
 
@@ -175,7 +174,7 @@ static gboolean trigger_udev_event_cb(GIOChannel *iochannel G_GNUC_UNUSED, GIOCo
         else
         {
             log_debug("Bad trigger data. Stopping\n");
-            watch_id = 0;
+            trigger_udev_input_id = 0;
             trigger_stop();
             return FALSE;
         }
@@ -187,26 +186,26 @@ static gboolean trigger_udev_event_cb(GIOChannel *iochannel G_GNUC_UNUSED, GIOCo
 
 void trigger_stop(void)
 {
-    if(watch_id)
+    if(trigger_udev_input_id)
     {
-        g_source_remove(watch_id);
-        watch_id = 0;
+        g_source_remove(trigger_udev_input_id);
+        trigger_udev_input_id = 0;
     }
-    if(iochannel) {
-        g_io_channel_unref(iochannel);
-        iochannel = NULL;
+    if(trigger_udev_iochannel) {
+        g_io_channel_unref(trigger_udev_iochannel);
+        trigger_udev_iochannel = NULL;
     }
-    if(mon)
+    if(trigger_udev_monitor)
     {
-        udev_monitor_unref(mon);
-        mon = 0;
+        udev_monitor_unref(trigger_udev_monitor);
+        trigger_udev_monitor = 0;
     }
-    if(udev)
+    if(trigger_udev_handle)
     {
-        udev_unref(udev);
-        udev = 0;
+        udev_unref(trigger_udev_handle);
+        trigger_udev_handle = 0;
     }
-    dev_name = 0;
+    trigger_udev_sysname = 0;
 }
 
 static void trigger_parse_udev_properties(struct udev_device *dev)