nfs4: always reset notified flag to false before repolling for lock

We may get a notification and lose the race to another client. Ensure
that we wait again for a notification in that case.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/nfs4proc.c

@@ -6673,6 +6673,7 @@ nfs4_retry_setlk(struct nfs4_state *state, int cmd, struct file_lock *request)
 	add_wait_queue(q, &wait);
 
 	while(!signalled()) {
+		waiter.notified = false;
 		status = nfs4_proc_setlk(state, cmd, request);
 		if ((status != -EAGAIN) || IS_SETLK(cmd))
 			break;