[mutter] monitor-config: Fix warning

[Jasper St. Pierre <jstpierre src gnome org>]

commit 89b14babb9babcab5bec8a42aab1aad9f77b4ee2
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Sat Nov 22 12:21:54 2014 -0800

    monitor-config: Fix warning

 src/backends/meta-monitor-config.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/backends/meta-monitor-config.c b/src/backends/meta-monitor-config.c
index c249e5d..5141bd6 100644
--- a/src/backends/meta-monitor-config.c
+++ b/src/backends/meta-monitor-config.c
@@ -1114,7 +1114,7 @@ make_suggested_config (MetaMonitorConfig *self,
   MetaOutput *primary;
   GList *region = NULL;
 
-  g_return_if_fail (config != NULL);
+  g_return_val_if_fail (config != NULL, FALSE);
   primary = find_primary_output (outputs, n_outputs);
 
   for (i = 0; i < n_outputs; i++)