be2net: fix be_vlan_add/rem_vid

1) fix be_vlan_add/rem_vid to return proper status
2) perform appropriate housekeeping if firmware command succeeds.

Signed-off-by: Ajit Khaparde <ajit.khaparde@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>