message: nydus-image: use fs_version to build tree
  For now we use Rafs v5 inode to build fs tree, will switch to v6 in
  the future.
diff: @@ -223,7 +223,7 @@ impl Display for Node {
  impl Node {
  pub fn new(
  - version: RafsVersion,
  + _version: RafsVersion,
  source: PathBuf,
  path: PathBuf,
  overlay: Overlay,
  @@ -243,7 +243,8 @@ impl Node {
  path,
  target_vec,
  overlay,
  - inode: InodeWrapper::new(version),
  + // liubo: for now, we use rafs v5 inode to build the whole tree.
  + inode: InodeWrapper::new(RafsVersion::V5),
  chunks: Vec::new(),
  symlink: None,
  xattrs: RafsXAttrs::default(),
  