If nlm_lookup_host finds what it is looking for it exits with an extra
reference on the matching 'nsm' structure.

So don't actually count the reference until we are (fairly) sure it is going
to be used.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>