[mutter] crtc: Don't leak MetaCrtcConfig

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 01aaced1293f360c81ceacb10ee69d6bf988c292
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Feb 26 16:54:25 2020 +0100

    crtc: Don't leak MetaCrtcConfig
    
    We never freed it except when CRTC disabled during runtime.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1095

 src/backends/meta-crtc.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/src/backends/meta-crtc.c b/src/backends/meta-crtc.c
index 2212c6ca9..7a38f5692 100644
--- a/src/backends/meta-crtc.c
+++ b/src/backends/meta-crtc.c
@@ -63,6 +63,8 @@ meta_crtc_finalize (GObject *object)
   if (crtc->driver_notify)
     crtc->driver_notify (crtc);
 
+  g_clear_pointer (&crtc->config, g_free);
+
   G_OBJECT_CLASS (meta_crtc_parent_class)->finalize (object);
 }