[mutter] meta_stack_tracker_free(): fix memory leak

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

commit 8a6a568aca9cc8fe4430d6a9b424a7fc005feaaf
Author: Pavel Vasin <rat4vier gmail com>
Date:   Fri Mar 23 11:59:11 2012 +0400

    meta_stack_tracker_free(): fix memory leak
    
    https://bugzilla.gnome.org/show_bug.cgi?id=672640

 src/core/stack-tracker.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/core/stack-tracker.c b/src/core/stack-tracker.c
index 585aa6c..d45a52b 100644
--- a/src/core/stack-tracker.c
+++ b/src/core/stack-tracker.c
@@ -394,6 +394,8 @@ meta_stack_tracker_free (MetaStackTracker *tracker)
   g_queue_foreach (tracker->queued_requests, (GFunc)meta_stack_op_free, NULL);
   g_queue_free (tracker->queued_requests);
   tracker->queued_requests = NULL;
+
+  g_free (tracker);
 }
 
 static void