scsi: fnic: bug fix for fip.fip_subcode in fnic_fcoe_send_vlan_req

This is a bug introduced when they moved the fip subcodes to central
place. Was sending FIP_SC_VL_NOTE in fip.fip_subcode for VLAN request in
fnic_fcoe_send_vlan_req. Change is to use FIP_SC_VL_REQ instead.

Signed-off-by: Satish Kharat <satishkh@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>