weston-resizor: Don't add new frame callbacks every click

The frame callback added on button click re-adds itself when done,
so adding a new one every click resulted in an ever increasing
number of callbacks.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Acked-by: Daniel Stone <daniels@collabora.com>

clients/resizor.c

@@ -53,6 +53,7 @@ struct resizor {
 	struct spring height;
 	struct wl_callback *frame_callback;
 	bool pointer_locked;
+	bool locked_frame_callback_registered;
 	struct input *locked_input;
 	float pointer_x;
 	float pointer_y;
@@ -330,11 +331,15 @@ button_handler(struct widget *widget,
 						  handle_pointer_unlocked);
 		resizor->locked_input = input;
 
+		if (resizor->locked_frame_callback_registered)
+			return;
+
 		surface = window_get_wl_surface(resizor->window);
 		callback = wl_surface_frame(surface);
 		wl_callback_add_listener(callback,
 					 &locked_pointer_frame_listener,
 					 resizor);
+		resizor->locked_frame_callback_registered = true;
 	} else if (button == BTN_LEFT &&
 		   state == WL_POINTER_BUTTON_STATE_RELEASED) {
 		input_set_pointer_image(input, CURSOR_LEFT_PTR);