dasd: cleanup dasd_scan_partitions

Use blkdev_get_by_dev instead of bdget_disk + blkdev_get.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/s390/block/dasd_genhd.c

@@ -101,18 +101,11 @@ int dasd_scan_partitions(struct dasd_block *block)
 	struct block_device *bdev;
 	int rc;
 
-	bdev = bdget_disk(block->gdp, 0);
-	if (!bdev) {
-		DBF_DEV_EVENT(DBF_ERR, block->base, "%s",
-			      "scan partitions error, bdget returned NULL");
-		return -ENODEV;
-	}
-
-	rc = blkdev_get(bdev, FMODE_READ, NULL);
-	if (rc < 0) {
+	bdev = blkdev_get_by_dev(disk_devt(block->gdp), FMODE_READ, NULL);
+	if (IS_ERR(bdev)) {
 		DBF_DEV_EVENT(DBF_ERR, block->base,
-			      "scan partitions error, blkdev_get returned %d",
-			      rc);
+			      "scan partitions error, blkdev_get returned %ld",
+			      PTR_ERR(bdev));
 		return -ENODEV;
 	}