workqueue: deprecate __cancel_delayed_work()

Now that cancel_delayed_work() can be safely called from IRQ handlers,
there's no reason to use __cancel_delayed_work().  Use
cancel_delayed_work() instead of __cancel_delayed_work() and mark the
latter deprecated.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Roland Dreier <roland@kernel.org>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 4898289..2b58905 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -434,7 +434,7 @@
  * if it returns 0 the timer function may be running and the queueing is in
  * progress.
  */
-static inline bool __cancel_delayed_work(struct delayed_work *work)
+static inline bool __deprecated __cancel_delayed_work(struct delayed_work *work)
 {
 	bool ret;