docs: Add missing transfer annotation to GtkBox

The gtk_box_get_center_widget function is missing a transfer annotation
for the returned widget. No transfer is done, so set transfer to none.

https://bugzilla.gnome.org/show_bug.cgi?id=728093

diff --git a/gtk/gtkbox.c b/gtk/gtkbox.c
index 6b9391eb8c0162444b6564fdc70d70cdefa20e04..557d9fdac2ce3fa94910d43b47119059543ebdd3 100644 (file)
--- a/gtk/gtkbox.c
+++ b/gtk/gtkbox.c
@@ -2614,7 +2614,7 @@ gtk_box_set_center_widget (GtkBox    *box,
  *
  * Retrieves the center widget of the box.
  *
- * Returns: the center widget
+ * Returns: (transfer none): the center widget
  *
  * Since: 3.12
  */