ide: fix refcounting in device drivers

During host driver module removal del_gendisk() results in a final
put on drive->gendev and freeing the drive by drive_release_dev().

Convert device drivers from using struct kref to use struct device
so device driver's object holds reference on ->gendev and prevents
drive from prematurely going away.

Also fix ->remove methods to not erroneously drop reference on a
host driver by using only put_device() instead of ide*_put().

Reported-by: Stanislaw Gruszka <stf_xl@wp.pl>
Tested-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/ide-cd.h b/drivers/ide/ide-cd.h
index ac40d6c..c878bfc 100644
--- a/drivers/ide/ide-cd.h
+++ b/drivers/ide/ide-cd.h
@@ -80,7 +80,7 @@
 	ide_drive_t		*drive;
 	struct ide_driver	*driver;
 	struct gendisk		*disk;
-	struct kref		kref;
+	struct device		dev;
 
 	/* Buffer for table of contents.  NULL if we haven't allocated
 	   a TOC buffer for this device yet. */