libata: clean up horkage handling

Horkage handling had the following problems.

* dev->horkage was positioned after ATA_DEVICE_CLEAR_OFFSET, so it was
  cleared before the device is configured.  This broke
  HORKAGE_DIAGNOSTIC.

* Some used dev->horkage while others called ata_device_blacklisted()
  directly.  This was at best confusing.

This patch moves dev->horkage right after dev->flags and set the field
according to the blacklist during device configuration.  All users
test against dev->horkage.  ata_device_blacklisted() now has only one
user, make it static.  While at it, rename it to ata_dev_blacklisted()
for consistency.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 0c8b657..47cd2a1 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -434,6 +434,7 @@
 	struct ata_port		*ap;
 	unsigned int		devno;		/* 0 or 1 */
 	unsigned long		flags;		/* ATA_DFLAG_xxx */
+	unsigned int		horkage;	/* List of broken features */
 	struct scsi_device	*sdev;		/* attached SCSI device */
 #ifdef CONFIG_ATA_ACPI
 	acpi_handle		acpi_handle;
@@ -465,7 +466,6 @@
 	/* error history */
 	struct ata_ering	ering;
 	int			spdn_cnt;
-	unsigned int		horkage;	/* List of broken features */
 };
 
 /* Offset into struct ata_device.  Fields above it are maintained
@@ -793,7 +793,6 @@
 extern void ata_id_c_string(const u16 *id, unsigned char *s,
 			    unsigned int ofs, unsigned int len);
 extern void ata_id_to_dma_mode(struct ata_device *dev, u8 unknown);
-extern unsigned long ata_device_blacklisted(const struct ata_device *dev);
 extern void ata_bmdma_setup (struct ata_queued_cmd *qc);
 extern void ata_bmdma_start (struct ata_queued_cmd *qc);
 extern void ata_bmdma_stop(struct ata_queued_cmd *qc);