scsi: pm80xx: Corrected dma_unmap_sg() parameter

For the function dma_unmap_sg(), the <nents> parameter should be number of
elements in the scatter list prior to the mapping, not after the mapping.
Signed-off-by: Deepak Ukey <deepak.ukey@microchip.com>
Signed-off-by: Viswas G <Viswas.G@microchip.com>
Acked-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/pm8001/pm8001_sas.c

@@ -488,7 +488,7 @@ static int pm8001_task_exec(struct sas_task *task,
 	dev_printk(KERN_ERR, pm8001_ha->dev, "pm8001 exec failed[%d]!\n", rc);
 	if (!sas_protocol_ata(t->task_proto))
 		if (n_elem)
-			dma_unmap_sg(pm8001_ha->dev, t->scatter, n_elem,
+			dma_unmap_sg(pm8001_ha->dev, t->scatter, t->num_scatter,
 				t->data_dir);
 out_done:
 	spin_unlock_irqrestore(&pm8001_ha->lock, flags);