[PATCH] nfsd4_lock() returns bogus values to clients

missing nfserrno() in default case of a switch by return value of
posix_lock_file(); as the result we send negative host-endian to clients that
expect positive network-endian, preferably mentioned in RFC...  BTW, that case
is not impossible - posix_lock_file() can return -ENOLCK and we do not handle
that one explicitly.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>