scsi: hisi_sas: use spin_lock_irqsave() for hisi_hba.lock

We used spin_lock() to grab hisi_hba.lock in two places where
spin_lock_irqsave() should be used, as hisi_hba.lock can be taken in
interrupt context.

This patch is to fix this.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>