Fix issue with empty mode list, add extra debug info

Signed-off-by: Philippe De Swert <philippe.deswert@jollamobile.com>

src/usb_moded-modesetting.c

@@ -315,6 +315,10 @@ void unset_dynamic_mode(void)
   struct mode_list_elem *data; 
 
   data = get_usb_mode_data();
+  /* the modelist could be empty */
+  if(!data)
+	return;
+
   if(data->sysfs_path)
   {
 	write_to_file(data->sysfs_path, data->sysfs_reset_value);

src/usb_moded-modules.c

@@ -133,6 +133,8 @@ int usb_moded_load_module(const char *module)
 	}
 	if( ret == 0)
 		log_info("Module %s loaded successfully\n", module);
+	else
+		log_info("Module %s failed to load\n", module);
 	return(ret);
 }
 

src/usb_moded.c

@@ -511,6 +511,7 @@ static gboolean charging_fallback(gpointer data)
   */
   free(current_mode.mode);
   current_mode.mode = strdup(MODE_ASK);
+  current_mode.data = NULL;
   charging_timeout = 0;
   log_info("Falling back on charging mode.\n");