[gtk/build-fix: 2/3] docs: Add missing annotation

[Emmanuele Bassi <ebassi src gnome org>]

commit 5cc6b3e342da5ef230a20af4f42a38af47cbf7ac
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Nov 1 12:54:35 2021 +0000

    docs: Add missing annotation

 gtk/gtkicontheme.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtkicontheme.c b/gtk/gtkicontheme.c
index 154c9d8794..5c88718356 100644
--- a/gtk/gtkicontheme.c
+++ b/gtk/gtkicontheme.c
@@ -2748,7 +2748,7 @@ add_key_to_hash (gpointer key,
  *
  * Lists the names of icons in the current icon theme.
  *
- * Returns: (element-type utf8) (transfer full): a string array
+ * Returns: (array zero-terminated=1) (element-type utf8) (transfer full): a string array
  *   holding the names of all the icons in the theme. You must
  *   free the array using g_strfreev().
  */