scsi: ufs: core: Improve SCSI abort handling

The following has been observed on a test setup:

WARNING: CPU: 4 PID: 250 at drivers/scsi/ufs/ufshcd.c:2737 ufshcd_queuecommand+0x468/0x65c
Call trace:
 ufshcd_queuecommand+0x468/0x65c
 scsi_send_eh_cmnd+0x224/0x6a0
 scsi_eh_test_devices+0x248/0x418
 scsi_eh_ready_devs+0xc34/0xe58
 scsi_error_handler+0x204/0x80c
 kthread+0x150/0x1b4
 ret_from_fork+0x10/0x30

That warning is triggered by the following statement:

	WARN_ON(lrbp->cmd);

Fix this warning by clearing lrbp->cmd from the abort handler.

Link: https://lore.kernel.org/r/20211104181059.4129537-1-bvanassche@acm.org
Fixes: 7a3e97b0 ("[SCSI] ufshcd: UFS Host controller driver")
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -7116,6 +7116,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
 		goto release;
 	}
 
+	lrbp->cmd = NULL;
 	err = SUCCESS;
 
 release: