scsi: hisi_sas: Drop free_irq() when devm_request_irq() failed

It will free irq automatically if devm_request_irq() failed, so drop
free_irq() if devm_request_irq() failed.

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>