[mutter] theme: Plug GdkPixbuf leak

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

commit 468b09c01efc3e461e6d1c0286922b25551a12fd
Author: Sebastian Keller <skeller src gnome org>
Date:   Mon Jan 6 20:48:01 2020 +0100

    theme: Plug GdkPixbuf leak
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/991

 src/ui/theme.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/ui/theme.c b/src/ui/theme.c
index 5f2b5fd8e..095b0f420 100644
--- a/src/ui/theme.c
+++ b/src/ui/theme.c
@@ -862,7 +862,7 @@ meta_frame_layout_draw_with_style (MetaFrameLayout         *layout,
             {
               GtkIconTheme *theme = gtk_icon_theme_get_default ();
               g_autoptr (GtkIconInfo) info = NULL;
-              GdkPixbuf *pixbuf;
+              g_autoptr (GdkPixbuf) pixbuf = NULL;
 
               info = gtk_icon_theme_lookup_icon_for_scale (theme, icon_name,
                                                            layout->icon_size, scale, 0);