xwm: remove configure_source on dispatch

This function is called also directly from weston_wm_window_set_toplevel(). If
configure_source is set at that point, simply resetting the pointer will "leak"
the source until it fires and calls this function again.

Let's keep the variable up-to-date by removing the source when called,
dispatched or not. This removes the second call. I only hope it doesn't cause
issues. This is also necessary if we intend to remove the source on window
destruction too.

Found by inspection.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.com>

xwayland/window-manager.c

@@ -2687,6 +2687,11 @@ weston_wm_window_configure(void *data)
 	uint32_t values[4];
 	int x, y, width, height;
 
+	if (window->configure_source) {
+		wl_event_source_remove(window->configure_source);
+		window->configure_source = NULL;
+	}
+
 	weston_wm_window_set_allow_commits(window, false);
 
 	weston_wm_window_get_child_position(window, &x, &y);
@@ -2709,8 +2714,6 @@ weston_wm_window_configure(void *data)
 				   XCB_CONFIG_WINDOW_HEIGHT,
 				   values);
 
-	window->configure_source = NULL;
-
 	weston_wm_window_schedule_repaint(window);
 }