lockd: make nlm_ntf_refcnt and nlm_ntf_wq static

The variables nlm_ntf_refcnt and nlm_ntf_wq are local to the source and
do not need to be in global scope, so make them static.

Cleans up sparse warnings:
fs/lockd/svc.c:60:10: warning: symbol 'nlm_ntf_refcnt' was not declared.
Should it be static?
fs/lockd/svc.c:61:1: warning: symbol 'nlm_ntf_wq' was not declared.
Should it be static?

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>