ceph: never send metrics if disable_send_metrics is set

Even the 'disable_send_metrics' is true so when the session is
being opened it will always trigger to send the metric for the
first time.

Cc: stable@vger.kernel.org
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Venky Shankar <vshankar@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/metric.c

@@ -216,7 +216,7 @@ static void metric_delayed_work(struct work_struct *work)
 	struct ceph_mds_client *mdsc =
 		container_of(m, struct ceph_mds_client, metric);
 
-	if (mdsc->stopping)
+	if (mdsc->stopping || disable_send_metrics)
 		return;
 
 	if (!m->session || !check_session_state(m->session)) {