Fix a few typos in the docs.
* @menu_button: the #GtkMenuButton
*
* User-provided callback function to create a popup for @menu_button on demand.
- * This function is called when the popoup of @menu_button is shown, but none has
- * been provided via gtk_menu_buton_set_popup(), gtk_menu_button_set_popover()
- * or gtk_menu_button_set_menu_model().
+ * This function is called when the popup of @menu_button is shown, but none has
+ * been provided via gtk_menu_button_set_popover() or gtk_menu_button_set_menu_model().
*/
typedef void (*GtkMenuButtonCreatePopupFunc) (GtkMenuButton *menu_button,
gpointer user_data);