window.c: Don't ungrab input after displaying the menu

We used to ungrab first to stop any existing grab and then grab after
showing the menu. That was broken in c680e90489, which
moved the ungrab down below the grab, and as a result menus are now
shown without a grab.  This commit moves the grab back up.

clients/window.c

@@ -4470,6 +4470,8 @@ window_show_menu(struct display *display,
 	window->x = x;
 	window->y = y;
 
+	input_ungrab(input);
+
 	widget_set_redraw_handler(menu->widget, menu_redraw_handler);
 	widget_set_enter_handler(menu->widget, menu_enter_handler);
 	widget_set_leave_handler(menu->widget, menu_leave_handler);
@@ -4482,7 +4484,6 @@ window_show_menu(struct display *display,
 	window_schedule_resize(window, frame_width(menu->frame),
 			       frame_height(menu->frame));
 
-	input_ungrab(input);
 	frame_interior(menu->frame, &ix, &iy, NULL, NULL);
 	wl_shell_surface_set_popup(window->shell_surface, input->seat,
 				   display_get_serial(window->display),