ui/dbus: fix leak regression

For some reason, during refactoring, an extra reference leak was introduced.

Fixes: commit 7945576cf2 ("ui/dbus: factor out sending a scanout")
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20260122113144.2046899-3-marcandre.lureau@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

ui/dbus-listener.c

@@ -815,8 +815,7 @@ static void ddl_scanout(DBusDisplayListener *ddl)
     qemu_dbus_display1_listener_call_scanout(
         ddl->proxy, surface_width(ddl->ds), surface_height(ddl->ds),
         surface_stride(ddl->ds), surface_format(ddl->ds), v_data,
-        G_DBUS_CALL_FLAGS_NONE, DBUS_DEFAULT_TIMEOUT, NULL, NULL,
-        g_object_ref(ddl));
+        G_DBUS_CALL_FLAGS_NONE, DBUS_DEFAULT_TIMEOUT, NULL, NULL, NULL);
 }
 
 static void dbus_gfx_update(DisplayChangeListener *dcl,