libata-acpi: fix _GTF command protocol for ATAPI devices

_GTF command is never ATA_PROT_ATAPI_NODATA whether the device is
ATAPI or not.  It's always ATA_PROT_NODATA.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 03a0acf..cb3eab6e 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -489,8 +489,7 @@
 
 	/* convert gtf to tf */
 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; /* TBD */
-	tf.protocol = atadev->class == ATA_DEV_ATAPI ?
-		ATA_PROT_ATAPI_NODATA : ATA_PROT_NODATA;
+	tf.protocol = ATA_PROT_NODATA;
 	tf.feature = gtf->tfa[0];	/* 0x1f1 */
 	tf.nsect   = gtf->tfa[1];	/* 0x1f2 */
 	tf.lbal    = gtf->tfa[2];	/* 0x1f3 */