[mutter] backends/x11: Ensure reply is initialised to NULL

[Jeremy Bicha <jbicha src gnome org>]

commit e9c9ee844c0a898689d9ae7e982ccced403a1b1b
Author: Ikey Doherty <michael i doherty intel com>
Date:   Fri Nov 6 03:29:05 2015 +0000

    backends/x11: Ensure reply is initialised to NULL

 src/backends/x11/meta-monitor-manager-xrandr.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/backends/x11/meta-monitor-manager-xrandr.c b/src/backends/x11/meta-monitor-manager-xrandr.c
index 4c41041..cc2d1de 100644
--- a/src/backends/x11/meta-monitor-manager-xrandr.c
+++ b/src/backends/x11/meta-monitor-manager-xrandr.c
@@ -359,7 +359,7 @@ output_get_backlight_limits_xrandr (MetaMonitorManagerXrandr *manager_xrandr,
 {
   Atom atom;
   xcb_connection_t *xcb_conn;
-  g_autofree xcb_randr_query_output_property_reply_t *reply;
+  g_autofree xcb_randr_query_output_property_reply_t *reply = NULL;
 
   atom = XInternAtom (manager_xrandr->xdisplay, "Backlight", False);