[SCSI] bnx2fc: Validate vlan id in NETDEV_UNREGISTER handler

When bnx2fc receives an UNREGISTER event on a vlan interface it calls
destroy on all interfaces that matches the physical interface. Add
vlan_id check to destroy only the vlan interface that generated the
event.

Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>