rename cancel_rearming_delayed_work() to cancel_delayed_work_sync()

Imho, the current naming of cancel_xxx workqueue functions is very confusing.

	cancel_delayed_work()
	cancel_rearming_delayed_work()
	cancel_rearming_delayed_workqueue()	// obsolete

	cancel_work_sync()

This looks as if the first 2 functions differ in "type" of their argument
which is not true any longer, nowadays the difference is the behaviour.

The semantics of cancel_rearming_delayed_work(dwork) was changed
significantly, it doesn't require that dwork rearms itself, and cancels dwork
synchronously.

Rename it to cancel_delayed_work_sync().  This matches cancel_delayed_work()
and cancel_work_sync().  Re-create cancel_rearming_delayed_work() as a simple
inline obsolete wrapper, like cancel_rearming_delayed_workqueue().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Jarek Poplawski <jarkao2@o2.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>