mlxsw: reg: Rename p_eth_proto_adm to full name p_eth_proto_admin

Rename p_eth_proto_adm to p_eth_proto_admin in mlxsw_reg_ptys_eth_unpack
function.

Signed-off-by: Shalom Toledo <shalomt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>