macintosh/ams: don't use flush_scheduled_work()

flush_scheduled_work() is deprecated and scheduled to be removed.
Directly flush ams_info.worker on detach instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/macintosh/ams/ams-core.c b/drivers/macintosh/ams/ams-core.c
index 2ad62c3..399beb16 100644
--- a/drivers/macintosh/ams/ams-core.c
+++ b/drivers/macintosh/ams/ams-core.c
@@ -226,7 +226,7 @@
 	 * We do this after ams_info.exit(), because an interrupt might
 	 * have arrived before disabling them.
 	 */
-	flush_scheduled_work();
+	flush_work_sync(&ams_info.worker);
 
 	/* Remove device */
 	of_device_unregister(ams_info.of_dev);