[PATCH] libata: separate out ata_id_major_version()

Separate out ATA major version calculation from ata_dev_identify()
into ata_id_major_version().  It's preparation for splitting
ata_dev_identify().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 4df5024..d87854e 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -927,7 +927,6 @@
 {
 	struct ata_device *dev = &ap->device[device];
 	unsigned int major_version;
-	u16 tmp;
 	unsigned long xfer_modes;
 	unsigned int using_edd;
 	struct ata_taskfile tf;
@@ -1030,10 +1029,7 @@
 			goto err_out_nosup;
 
 		/* get major version */
-		tmp = dev->id[ATA_ID_MAJOR_VER];
-		for (major_version = 14; major_version >= 1; major_version--)
-			if (tmp & (1 << major_version))
-				break;
+		major_version = ata_id_major_version(dev->id);
 
 		/*
 		 * The exact sequence expected by certain pre-ATA4 drives is: