rtc: don't use flush_scheduled_work()

flush_scheduled_work() is deprecated and scheduled to be removed.  On
removal, directly cancel the work, and flush the uie_task in
rtc-dev.c::clear_uie().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: rtc-linux@googlegroups.com
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index 62227cd..0cc0984 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -104,7 +104,7 @@
 		}
 		if (rtc->uie_task_active) {
 			spin_unlock_irq(&rtc->irq_lock);
-			flush_scheduled_work();
+			flush_work_sync(&rtc->uie_task);
 			spin_lock_irq(&rtc->irq_lock);
 		}
 		rtc->uie_irq_active = 0;