scsi: fcoe: filter out frames from invalid vlans

Any multicase address is set on all interfaces, the base interface
and any VLAN interfaces on top of this. So we might receive frames
which are not destined for us.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>