scsi: fnic: Remove set but not used 'eth_hdrs_stripped'

scsi: fnic: Remove set but not used 'eth_hdrs_stripped'

This addresses the following gcc warning with "make W=1":

drivers/scsi/fnic/fnic_fcs.c: In function ‘fnic_rq_cmpl_frame_recv’:
drivers/scsi/fnic/fnic_fcs.c:840:15: warning: variable
‘eth_hdrs_stripped’ set but not used [-Wunused-but-set-variable]
  840 |  unsigned int eth_hdrs_stripped;
      |               ^~~~~~~~~~~~~~~~~

Link: https://lore.kernel.org/r/20200831081126.3251288-5-yanaijie@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>