pata_it821x: use raw nbytes in check_atapi_dma

pata_it821x needs to look at raw request size in check_atapi_dma().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/ata/pata_it821x.c

@@ -564,7 +564,7 @@ static int it821x_check_atapi_dma(struct ata_queued_cmd *qc)
 	struct it821x_dev *itdev = ap->private_data;
 
 	/* Only use dma for transfers to/from the media. */
-	if (qc->nbytes < 2048)
+	if (ata_qc_raw_nbytes(qc) < 2048)
 		return -EOPNOTSUPP;
 
 	/* No ATAPI DMA in smart mode */