We don't have any users, and it is not so trivial to use NOAUTOREL works
correctly.  It is better to simplify API.

Delete NOAUTOREL support and rename work_release to work_clear_pending to
avoid a confusion.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>