scsi: lpfc: remove redundant assignment of sgel

From: Colin Ian King <colin.king@canonical.com>

In the NVMET_FCOP_RSP case, sgel is assigned but never used and
hence is redundant and can be removed.

Detected by CoverityScan, CID#1411658 ("Unused value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>