[mutter] backends/x11: Fix memory leak in meta_x11_handle_event()

[Marge Bot <marge-bot src gnome org>]

commit 97dd5d887718ebf575505091eae05735a88cb5a5
Author: Sebastian Keller <skeller gnome org>
Date:   Sun Jan 2 03:55:14 2022 +0100

    backends/x11: Fix memory leak in meta_x11_handle_event()
    
    The event was leaked after it had been processed.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2192>

 src/backends/x11/meta-event-x11.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/backends/x11/meta-event-x11.c b/src/backends/x11/meta-event-x11.c
index d230a3406f..e6483a8156 100644
--- a/src/backends/x11/meta-event-x11.c
+++ b/src/backends/x11/meta-event-x11.c
@@ -103,6 +103,7 @@ meta_x11_handle_event (XEvent *xevent)
     {
       /* forward the event into clutter for emission etc. */
       clutter_do_event (event);
+      clutter_event_free (event);
       --spin;
     }