[mutter] x11: Initialize g_autofree with NULL

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

commit 70f2eb7bfaa8d24bb8c79176e758181f2e95bcbf
Author: Dor Askayo <dor askayo gmail com>
Date:   Sat Sep 4 22:53:37 2021 +0300

    x11: Initialize g_autofree with NULL
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1990>

 src/x11/meta-x11-display.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/x11/meta-x11-display.c b/src/x11/meta-x11-display.c
index 8b446e3485..502b1a9622 100644
--- a/src/x11/meta-x11-display.c
+++ b/src/x11/meta-x11-display.c
@@ -924,7 +924,7 @@ set_workspace_work_area_hint (MetaWorkspace  *workspace,
   int num_monitors;
   unsigned long *data;
   unsigned long *tmp;
-  g_autofree char *workarea_name;
+  g_autofree char *workarea_name = NULL;
   Atom workarea_atom;
 
   monitor_manager = meta_backend_get_monitor_manager (meta_get_backend ());