[metacity] theme-metacity: fix memory leak

[Alberts Muktupāvels <muktupavels src gnome org>]

commit e3196fb9a05bf27e27eabf06f7b5068dfbf14998
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Mar 14 20:53:26 2021 +0200

    theme-metacity: fix memory leak
    
    Coverity CID: #1502680

 libmetacity/meta-theme-metacity.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/libmetacity/meta-theme-metacity.c b/libmetacity/meta-theme-metacity.c
index 831086c63..2161a7ccf 100644
--- a/libmetacity/meta-theme-metacity.c
+++ b/libmetacity/meta-theme-metacity.c
@@ -2303,6 +2303,8 @@ parse_draw_op_element (GMarkupParseContext  *context,
       if (alpha && !parse_alpha (alpha, &alpha_spec, context, error))
         {
           g_object_unref (G_OBJECT (pixbuf));
+          if (colorize_spec != NULL)
+            meta_color_spec_free (colorize_spec);
           return;
         }