pnfs/blocklayout: Fix memory leak in bl_parse_scsi()

In bl_parse_scsi(), if the block device length is zero, the function
returns immediately without releasing the file reference obtained via
bl_open_path(), leading to a memory leak.

Fix this by jumping to the out_blkdev_put label to ensure the file
reference is properly released.

Fixes: d76c769c8db4c ("pnfs/blocklayout: Don't add zero-length pnfs_block_dev")
Signed-off-by: Zilin Guan <[e-mail]>
Signed-off-by: Trond Myklebust <[e-mail]>

fs/nfs/blocklayout/dev.c

···
 	d->map = bl_map_simple;
 	d->pr_key = v->scsi.pr_key;
 
-	if (d->len == 0)
-		return -ENODEV;
+	if (d->len == 0) {
+		error = -ENODEV;
+		goto out_blkdev_put;
+	}
 
 	ops = bdev->bd_disk->fops->pr_ops;
 	if (!ops) {