bridge: vlan_tunnel: explicitly reset metadata attrs to NULL on failure

Fixes: efa5356b ("bridge: per vlan dst_metadata netlink support")
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_vlan_tunnel.c

@@ -85,6 +85,8 @@ static int __vlan_tunnel_info_add(struct net_bridge_vlan_group *vg,
 	return 0;
 out:
 	dst_release(&vlan->tinfo.tunnel_dst->dst);
+	vlan->tinfo.tunnel_dst = NULL;
+	vlan->tinfo.tunnel_id = 0;
 
 	return err;
 }