LOCKD: Clear ln->nsm_clnt only when ln->nsm_users is zero

The current code is clearing it in all cases _except_ when zero.
Reported-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

fs/lockd/mon.c

@@ -124,18 +124,16 @@ static struct rpc_clnt *nsm_client_get(struct net *net)
 static void nsm_client_put(struct net *net)
 {
 	struct lockd_net *ln = net_generic(net, lockd_net_id);
-	struct rpc_clnt	*clnt = ln->nsm_clnt;
-	int shutdown = 0;
+	struct rpc_clnt	*clnt = NULL;
 
 	spin_lock(&ln->nsm_clnt_lock);
-	if (ln->nsm_users) {
-		if (--ln->nsm_users)
-			ln->nsm_clnt = NULL;
-		shutdown = !ln->nsm_users;
+	ln->nsm_users--;
+	if (ln->nsm_users == 0) {
+		clnt = ln->nsm_clnt;
+		ln->nsm_clnt = NULL;
 	}
 	spin_unlock(&ln->nsm_clnt_lock);
-
-	if (shutdown)
+	if (clnt != NULL)
 		rpc_shutdown_client(clnt);
 }