scsi: lpfc: Avoid another null dereference in lpfc_sli4_hba_unset()

scsi: lpfc: Avoid another null dereference in lpfc_sli4_hba_unset()

Commit dbf6f0f62e75 ("scsi: lpfc: Replace io_channels for nvme and fcp with
general hdw_queues per cpu") has introduced static checker warnings for
potential null dereferences in 'lpfc_sli4_hba_unset()' and commit 9a9f65701aaf
("scsi: lpfc: resolve static checker warning in lpfc_sli4_hba_unset") has
tried to fix it.  However, yet another potential null dereference is
remaining.  This commit fixes it.

This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.

Link: https://lore.kernel.org/r/20200623084122.30633-1-sjpark@amazon.com
Fixes: 9a9f65701aaf ("scsi: lpfc: resolve static checker warning inlpfc_sli4_hba_unset")
Fixes: dbf6f0f62e75 ("scsi: lpfc: Replace io_channels for nvme and fcp with general hdw_queues per cpu")
Reviewed-by: James Smart <james.smart@broadcom.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>