scsi: fnic: Remove set but not used variable 'vdev'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/scsi/fnic/vnic_wq.c: In function 'vnic_wq_alloc_bufs':
drivers/scsi/fnic/vnic_wq.c:50:19: warning:
 variable 'vdev' set but not used [-Wunused-but-set-variable]

drivers/scsi/fnic/vnic_rq.c: In function 'vnic_rq_alloc_bufs':
drivers/scsi/fnic/vnic_rq.c:30:19: warning:
 variable 'vdev' set but not used [-Wunused-but-set-variable]

Never used since introduction.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Satish Kharat <satishkh@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>