workqueue: make delayed_work_timer_fn() static

delayed_work_timer_fn() is a timer function, make it static.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/timer.h b/include/linux/timer.h
index ffe438a..979fefd 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -124,8 +124,6 @@
 }
 #endif
 
-extern void delayed_work_timer_fn(unsigned long __data);
-
 /**
  * add_timer - start a timer
  * @timer: the timer to be added
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 3f168e0..ff06611 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -175,7 +175,7 @@
 }
 EXPORT_SYMBOL_GPL(queue_work);
 
-void delayed_work_timer_fn(unsigned long __data)
+static void delayed_work_timer_fn(unsigned long __data)
 {
 	struct delayed_work *dwork = (struct delayed_work *)__data;
 	struct cpu_workqueue_struct *cwq = get_wq_data(&dwork->work);