scsi: hisi_sas: Remove unused parameter of function hisi_sas_alloc()

In function hisi_sas_alloc(), parameter shost is not used, so remove it.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>