libata: straighten out ATA_ID_* constants

* Kill _OFS suffixes in ATA_ID_{SERNO|FW_REV|PROD}_OFS for consistency
  with other ATA_ID_* constants.

* Kill ATA_SERNO_LEN

* Add and use ATA_ID_SERNO_LEN, ATA_ID_FW_REV_LEN and ATA_ID_PROD_LEN.
  This change also makes ata_device_blacklisted() use proper length
  for fwrev.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 1df9416..3a50739 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -44,9 +44,9 @@
 	ATA_MAX_SECTORS_LBA48	= 65535,/* TODO: 65536? */
 
 	ATA_ID_WORDS		= 256,
-	ATA_ID_SERNO_OFS	= 10,
-	ATA_ID_FW_REV_OFS	= 23,
-	ATA_ID_PROD_OFS		= 27,
+	ATA_ID_SERNO		= 10,
+	ATA_ID_FW_REV		= 23,
+	ATA_ID_PROD		= 27,
 	ATA_ID_OLD_PIO_MODES	= 51,
 	ATA_ID_FIELD_VALID	= 53,
 	ATA_ID_MWDMA_MODES	= 63,
@@ -58,8 +58,11 @@
 	ATA_ID_MAJOR_VER	= 80,
 	ATA_ID_PIO4		= (1 << 1),
 
+	ATA_ID_SERNO_LEN	= 20,
+	ATA_ID_FW_REV_LEN	= 8,
+	ATA_ID_PROD_LEN		= 40,
+
 	ATA_PCI_CTL_OFS		= 2,
-	ATA_SERNO_LEN		= 20,
 	ATA_UDMA0		= (1 << 0),
 	ATA_UDMA1		= ATA_UDMA0 | (1 << 1),
 	ATA_UDMA2		= ATA_UDMA1 | (1 << 2),