[PATCH] sanitize blkdev_get() and friends

* get rid of fake struct file/struct dentry in __blkdev_get()
* merge __blkdev_get() and do_open()
* get rid of flags argument of blkdev_get()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
index 3c1b691..e99d566 100644
--- a/drivers/s390/block/dasd_genhd.c
+++ b/drivers/s390/block/dasd_genhd.c
@@ -99,7 +99,7 @@
 	struct block_device *bdev;
 
 	bdev = bdget_disk(block->gdp, 0);
-	if (!bdev || blkdev_get(bdev, FMODE_READ, 1) < 0)
+	if (!bdev || blkdev_get(bdev, FMODE_READ) < 0)
 		return -ENODEV;
 	/*
 	 * See fs/partition/check.c:register_disk,rescan_partitions