be2net: remove unused code in be_cmd_vlan_config()

For putting interface into vlan promiscuous mode, we use be_cmd_rx_filter()
and not be_cmd_vlan_config(). So remove the "promiscuous" argument from
be_cmd_vlan_config().

Signed-off-by: Kalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>