[SCSI] libsas: convert to use the data buffer accessors

- convert to use the new accessors for the sg lists and the
parameters.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/libsas/sas_scsi_host.c

@@ -76,8 +76,8 @@ static void sas_scsi_task_done(struct sas_task *task)
 			hs = DID_NO_CONNECT;
 			break;
 		case SAS_DATA_UNDERRUN:
-			sc->resid = ts->residual;
-			if (sc->request_bufflen - sc->resid < sc->underflow)
+			scsi_set_resid(sc, ts->residual);
+			if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
 				hs = DID_ERROR;
 			break;
 		case SAS_DATA_OVERRUN:
@@ -161,9 +161,9 @@ static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
 	task->ssp_task.task_attr = sas_scsi_get_task_attr(cmd);
 	memcpy(task->ssp_task.cdb, cmd->cmnd, 16);
 
-	task->scatter = cmd->request_buffer;
-	task->num_scatter = cmd->use_sg;
-	task->total_xfer_len = cmd->request_bufflen;
+	task->scatter = scsi_sglist(cmd);
+	task->num_scatter = scsi_sg_count(cmd);
+	task->total_xfer_len = scsi_bufflen(cmd);
 	task->data_dir = cmd->sc_data_direction;
 
 	task->task_done = sas_scsi_task_done;