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

drivers/scsi/pm8001/pm8001_hwi.c: In function 'mpi_smp_completion':
drivers/scsi/pm8001/pm8001_hwi.c:2901:6: warning:
 variable 'param' set but not used [-Wunused-but-set-variable]

drivers/scsi/pm8001/pm8001_hwi.c: In function 'pm8001_bytes_dmaed':
drivers/scsi/pm8001/pm8001_hwi.c:3247:24: warning:
 variable 'sas_ha' set but not used [-Wunused-but-set-variable]

They're never used since introduction, so can be removed.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>