message: nydus-image: show error when failing on reading blob meta info
diff: @@ -508,7 +508,7 @@ impl BlobMetaInfo {
  let size = reader
  .read(&mut buf, blob_info.meta_ci_offset())
  - .map_err(|_e| eio!("failed to read metadata from backend"))?;
  + .map_err(|e| eio!(format!("failed to read metadata from backend, {:?}", e)))?;
  if size as u64 != compressed_size {
  return Err(eio!("failed to read blob metadata from backend"));
  }
  