Bug Fix: Non NFSD conflicting byte-range locks were causing an Oops.

Encode a zero length owner and zero clientid for non NFSD conflicting locks in
the lock_denied response.
Signed-off-by: Andy Adamson <andros@umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>