[PATCH] knfsd: fix nfs4_open lock leak

I just noticed that my patch "don't create on open that fails due to
ERR_GRACE" (recently commited as fb553c0f)
had an obvious problem that causes a deadlock on reboot recovery.  Sending
in this now since it seems like a clear 2.6.16 candidate.--b.

We're returning with a lock held in some error cases.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>