[mutter] ui: Suppress warnings from -Werror=maybe-uninitialized

[Debarshi Ray <debarshir src gnome org>]

commit b9f775fe02e9bc6d2d48b3c47f076d51aede8813
Author: Debarshi Ray <debarshir gnome org>
Date:   Thu Jan 3 16:18:41 2013 +0100

    ui: Suppress warnings from -Werror=maybe-uninitialized

 src/ui/ui.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/ui/ui.c b/src/ui/ui.c
index ce108a7..1fe5cd4 100644
--- a/src/ui/ui.c
+++ b/src/ui/ui.c
@@ -116,8 +116,8 @@ maybe_redirect_mouse_event (XEvent *xevent)
   GdkWindow *gdk_window;
   Window window;
   XIEvent *xev;
-  XIDeviceEvent *xev_d;
-  XIEnterEvent *xev_e;
+  XIDeviceEvent *xev_d = NULL;
+  XIEnterEvent *xev_e = NULL;
 
   if (!is_input_event (xevent))
     return FALSE;