[gtk/matthiasc/for-master: 4/6] menubutton: Fix a gtk-doc complaint

[Matthias Clasen <matthiasc src gnome org>]

commit c235783f6fb6be96a75a6cd9fd00ea3012c2a7e0
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Nov 16 22:45:59 2020 -0500

    menubutton: Fix a gtk-doc complaint

 gtk/gtkmenubutton.h | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gtk/gtkmenubutton.h b/gtk/gtkmenubutton.h
index 6f67ad393a..e9011f93fd 100644
--- a/gtk/gtkmenubutton.h
+++ b/gtk/gtkmenubutton.h
@@ -39,6 +39,7 @@ typedef struct _GtkMenuButton        GtkMenuButton;
 /**
  * GtkMenuButtonCreatePopupFunc:
  * @menu_button: the #GtkMenuButton
+ * @user_data: User data passed to gtk_menu_button_set_create_popup_func()
  *
  * User-provided callback function to create a popup for @menu_button on demand.
  * This function is called when the popup of @menu_button is shown, but none has