core: use G_SOURCE_REMOVE and G_SOURCE_CONTINUE in GSourceFuncs

plugins/option/mm-broadband-bearer-hso.c

@@ -438,7 +438,7 @@ connect_timed_out_cb (MMBroadbandBearerHso *self)
     /* It's probably pointless to try to reset this here, but anyway... */
     connect_reset (ctx);
 
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 static void

plugins/option/mm-broadband-modem-option.c

@@ -675,7 +675,7 @@ after_power_up_wait_cb (GSimpleAsyncResult *result)
     option->priv->after_power_up_wait_id = 0;
     g_object_unref (option);
 
-    return FALSE;
+    return G_SOURCE_REMOVE;
 }
 
 static void