be2net: clear vlan-promisc setting before programming the vlan list

The Lancer FW has a bug due to which in some cases vlan-promisc setting
is cleared eventhough the vlan-list programming did not succeed (via
VLAN_CONFIG) cmd. The driver has no way of knowing if the vlan-promisc
mode was cleared or not when this cmd fails. To work around this issue,
this patch first explicitly clears the vlan-promisc mode via RX_FILTER
cmd and then tries to program the vlan list.
Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>

Signed-off-by: Sathya Perla <sathya.perla@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>