message: nydus-image: fix inspect wrong chunk offset
  To read chunks, the reader must seek to the inode table
  offset + inode struct size + extra attributes size.
  To get inode struct size, the inode.inode_size() shold
  be used, the inode.size() will only return the
  file size the inode reprents.
diff: @@ -179,7 +179,7 @@ impl RafsInspector {
  let mut chunks = None;
  if inode.has_xattr() {
  - let xattr_header_offset = inode_offset + inode.size() as u32;
  + let xattr_header_offset = inode_offset + inode.inode_size() as u32;
  r.seek_to_offset(xattr_header_offset as u64)?;
  // TODO: implement `load()` for `OndiskXattr`
  let mut xattrs_header = RafsV5XAttrsTable::new();
  @@ -187,7 +187,7 @@ impl RafsInspector {
  xattr_pairs_aligned_size = xattrs_header.aligned_size() as u32 + 8;
  }
  - let chunks_offset = inode_offset + inode.size() as u32 + xattr_pairs_aligned_size;
  + let chunks_offset = inode_offset + inode.inode_size() as u32 + xattr_pairs_aligned_size;
  r.seek_to_offset(chunks_offset as u64)?;
  