a) ERR_PTR(nfserr_something) is a bad idea;
IS_ERR() will be false for it.
	b) mixing nfserr_.... with -EOPNOTSUPP is
even worse idea.

nfsd4_path() does both; caller expects to get NFS protocol error out it if
anything goes wrong, but if it does we either do not notice (see (a)) or get
host-endian negative (see (b)).

IOW, that's a case when we can't use ERR_PTR() to return error, even though we
return a pointer in case of success.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>