Several failure exits return -E<something> instead of nfserr_<something> and
vice versa.

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>