be2net: re-enable vlan filtering mode asap

While adding vlans, when the HW limit of vlan filters is reached, the
driver enables vlan promiscuous mode.
Similarily, while removing vlans, the driver must re-enable HW filtering
as soon as the number of vlan filters is within the HW limit.

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>