[PATCH] unexport add_timer_on()

add_timer_on() isn't used by modules (in fact it's only used ONCE, in
workqueue.c) and it's not even a good api for drivers, in fact, the comment
for it says

 * This is not very scalable on SMP. Double adds are not possible.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/timer.c

@@ -241,7 +241,6 @@ void add_timer_on(struct timer_list *timer, int cpu)
 	spin_unlock_irqrestore(&base->lock, flags);
 }
 
-EXPORT_SYMBOL(add_timer_on);
 
 /***
  * mod_timer - modify a timer's timeout