libata: implement protocol tests

Implement protocol tests - ata_is_atapi(), ata_is_nodata(),
ata_is_pio(), ata_is_dma(), ata_is_ncq() and ata_is_data() and use
them to replace is_atapi_taskfile() and hard coded protocol tests.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 0829b55..831294d 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -176,7 +176,7 @@
 
 	ata_tf_to_fis(&qc->tf, 1, 0, (u8*)&task->ata_task.fis);
 	task->uldd_task = qc;
-	if (is_atapi_taskfile(&qc->tf)) {
+	if (ata_is_atapi(qc->tf.protocol)) {
 		memcpy(task->ata_task.atapi_packet, qc->cdb, qc->dev->cdb_len);
 		task->total_xfer_len = qc->nbytes + qc->pad_len;
 		task->num_scatter = qc->pad_len ? qc->n_elem + 1 : qc->n_elem;