[network] Fix potential memory leak. Fixes: CID#1311255, CID#1311254,…

… CID#1311253, CID#1311252

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

src/usb_moded-network.c

@@ -337,6 +337,10 @@ static int write_udhcpd_conf(struct ipforward_data *ipforward, struct mode_list_
 	return(1);
   }
 
+  interface = get_interface(data);
+  if(interface == NULL)
+	return(1);
+
   /* generate start and end ip based on the setting */
   ip = get_network_ip();
   if(ip == NULL)
@@ -365,9 +369,6 @@ static int write_udhcpd_conf(struct ipforward_data *ipforward, struct mode_list_
   strcat(ipstart,"1");
   strcat(ipend, "10");
 
-  interface = get_interface(data);
-  if(interface == NULL)
-	return(1);
   /* print all data in the file */
   fprintf(conffile, "start\t%s\n", ipstart);
   fprintf(conffile, "end\t%s\n", ipend);