[gnome-flashback] status-notifier-watcher: fix unchecked return value warning

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 0d5fbec38ddf71aa63b3a7578ebb335b4bd1a9f1
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Thu Mar 12 15:34:05 2020 +0200

    status-notifier-watcher: fix unchecked return value warning
    
    CID 1445685.

 gnome-flashback/libstatus-notifier-watcher/gf-sn-watcher-v0.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/gnome-flashback/libstatus-notifier-watcher/gf-sn-watcher-v0.c 
b/gnome-flashback/libstatus-notifier-watcher/gf-sn-watcher-v0.c
index 3f5c556..fe24875 100644
--- a/gnome-flashback/libstatus-notifier-watcher/gf-sn-watcher-v0.c
+++ b/gnome-flashback/libstatus-notifier-watcher/gf-sn-watcher-v0.c
@@ -330,15 +330,18 @@ bus_acquired_cb (GDBusConnection *connection,
   GfSnWatcherV0 *v0;
   GDBusInterfaceSkeleton *skeleton;
   GError *error;
+  gboolean exported;
 
   v0 = GF_SN_WATCHER_V0 (user_data);
   skeleton = G_DBUS_INTERFACE_SKELETON (v0);
 
   error = NULL;
-  g_dbus_interface_skeleton_export (skeleton, connection,
-                                    "/StatusNotifierWatcher", &error);
+  exported = g_dbus_interface_skeleton_export (skeleton,
+                                               connection,
+                                               "/StatusNotifierWatcher",
+                                               &error);
 
-  if (error != NULL)
+  if (!exported)
     {
       g_warning ("%s", error->message);
       g_error_free (error);