[PATCH] libata: seperate out ata_class_present()

Seperate out ata_class_present() from ata_dev_present().  This is
useful because new reset mechanism deals with classes[] directly.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

include/linux/libata.h

@@ -645,10 +645,14 @@ static inline unsigned int ata_tag_valid(unsigned int tag)
 	return (tag < ATA_MAX_QUEUE) ? 1 : 0;
 }
 
+static inline unsigned int ata_class_present(unsigned int class)
+{
+	return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI;
+}
+
 static inline unsigned int ata_dev_present(const struct ata_device *dev)
 {
-	return ((dev->class == ATA_DEV_ATA) ||
-		(dev->class == ATA_DEV_ATAPI));
+	return ata_class_present(dev->class);
 }
 
 static inline u8 ata_chk_status(struct ata_port *ap)