gnome: use g_clear_error to free GError

This sets the GError to NULL after freeing it
which is useful in cases where the GError might
be re-used.

Refs #72309

Change-Id: If3c33235378bc080b497bed732570f17e8e6d3e9
diff --git a/src/dialogs.c b/src/dialogs.c
index becbbd2..657057c 100644
--- a/src/dialogs.c
+++ b/src/dialogs.c
@@ -86,7 +86,7 @@
     GdkPixbuf* logo = gdk_pixbuf_new_from_resource("/cx/ring/RingGnome/ring-logo-blue", &error);
     if (logo == NULL) {
         g_debug("Could not load logo: %s", error->message);
-        g_error_free(error);
+        g_clear_error(&error);
     }
 
     gchar *name = g_strdup_printf("Gnome Ring v%d.%d.%d", VERSION_MAJOR, VERSION_MINOR, VERSION_PATCH);