NSM: Remove BUG_ON() in nsm_monitor()

Clean up: Remove the BUG_ON() invocation in nsm_monitor().  It's not
likely that nsm_monitor() is ever called with a NULL host pointer, and
the code will die anyway if host is NULL.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/lockd/mon.c

@@ -80,7 +80,6 @@ nsm_monitor(struct nlm_host *host)
 	int		status;
 
 	dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
-	BUG_ON(nsm == NULL);
 
 	if (nsm->sm_monitored)
 		return 0;