use ATA_TAG_INTERNAL in ata_tag_internal()

It should be ATA_TAG_INTERNAL.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

include/linux/libata.h

@@ -1121,7 +1121,7 @@ static inline unsigned int ata_tag_valid(unsigned int tag)
 
 static inline unsigned int ata_tag_internal(unsigned int tag)
 {
-	return tag == ATA_MAX_QUEUE - 1;
+	return tag == ATA_TAG_INTERNAL;
 }
 
 /*