drbd: Renamed the net_conf_update mutex to conf_update

Preparing to use the same mutex for disk_conf updates

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 523ec09..332781c 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -1410,11 +1410,11 @@
 	if (oc == C_DISCONNECTING && ns_max.conn == C_STANDALONE) {
 		struct net_conf *old_conf;
 
-		mutex_lock(&tconn->net_conf_update);
+		mutex_lock(&tconn->conf_update);
 		old_conf = tconn->net_conf;
 		rcu_assign_pointer(tconn->net_conf, NULL);
 		conn_free_crypto(tconn);
-		mutex_unlock(&tconn->net_conf_update);
+		mutex_unlock(&tconn->conf_update);
 
 		synchronize_rcu();
 		kfree(old_conf);