scsi: qla2xxx: Remove redundant NULL check

Fix below warnings reported by coccicheck:
./drivers/scsi/qla2xxx/qla_init.c:3371:2-7: WARNING: NULL check before
some freeing functions is not needed.
./drivers/scsi/qla2xxx/qla_init.c:7855:5-10: WARNING: NULL check before
some freeing functions is not needed.
./drivers/scsi/qla2xxx/qla_init.c:7916:2-7: WARNING: NULL check before
some freeing functions is not needed.
./drivers/scsi/qla2xxx/qla_init.c:8113:4-18: WARNING: NULL check before
some freeing functions is not needed.
./drivers/scsi/qla2xxx/qla_init.c:8174:2-7: WARNING: NULL check before
some freeing functions is not needed.

Link: https://lore.kernel.org/r/1611306174-92627-1-git-send-email-abaci-bugfix@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Yang Li <abaci-bugfix@linux.alibaba.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>