scsi: hisi_sas: lock sensitive region in hisi_sas_slot_abort()

When we call hisi_sas_slot_task_free() we should grab the hisi_hba.lock,
as hisi_sas_slot_task_free() accesses common hisi_hba elements.
Function hisi_sas_slot_abort() is missing this, so add it.
Signed-off-by: John Garry <john.garry@huawei.com>
Reviewed-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -146,6 +146,7 @@ static void hisi_sas_slot_abort(struct work_struct *work)
 	struct scsi_lun lun;
 	struct device *dev = &hisi_hba->pdev->dev;
 	int tag = abort_slot->idx;
+	unsigned long flags;
 
 	if (!(task->task_proto & SAS_PROTOCOL_SSP)) {
 		dev_err(dev, "cannot abort slot for non-ssp task\n");
@@ -159,7 +160,9 @@ static void hisi_sas_slot_abort(struct work_struct *work)
 	hisi_sas_debug_issue_ssp_tmf(task->dev, lun.scsi_lun, &tmf_task);
 out:
 	/* Do cleanup for this task */
+	spin_lock_irqsave(&hisi_hba->lock, flags);
 	hisi_sas_slot_task_free(hisi_hba, task, abort_slot);
+	spin_unlock_irqrestore(&hisi_hba->lock, flags);
 	if (task->task_done)
 		task->task_done(task);
 	if (sas_dev)