net: bridge: declare br_vlan_tunnel_lookup argument tunnel_id as __be64

The only caller of br_vlan_tunnel_lookup, br_handle_ingress_vlan_tunnel,
extracts the tunnel_id from struct ip_tunnel_info::struct ip_tunnel_key::
tun_id which is a __be64 value.

The exact endianness does not seem to matter, because the tunnel id is
just used as a lookup key for the VLAN group's tunnel hash table, and
the value is not interpreted directly per se. Moreover,
rhashtable_lookup_fast treats the key argument as a const void *.

Therefore, there is no functional change associated with this patch,
just one to silence "make W=1" builds.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>