relay: use plain timer instead of delayed work

relay doesn't need to use schedule_delayed_work() for waking readers
when a simple timer will do.

Signed-off-by: Tom Zanussi <zanussi@comcast.net>
Cc: Satyam Sharma <satyam.sharma@gmail.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/relay.h b/include/linux/relay.h
index 759a0f9..6cd8c44 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -12,6 +12,7 @@
 
 #include <linux/types.h>
 #include <linux/sched.h>
+#include <linux/timer.h>
 #include <linux/wait.h>
 #include <linux/list.h>
 #include <linux/fs.h>
@@ -38,7 +39,7 @@
 	size_t subbufs_consumed;	/* count of sub-buffers consumed */
 	struct rchan *chan;		/* associated channel */
 	wait_queue_head_t read_wait;	/* reader wait queue */
-	struct delayed_work wake_readers; /* reader wake-up work struct */
+	struct timer_list timer; 	/* reader wake-up timer */
 	struct dentry *dentry;		/* channel file dentry */
 	struct kref kref;		/* channel buffer refcount */
 	struct page **page_array;	/* array of current buffer pages */