use fmt for better readibility

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

pkg/storage/fs/ocis/node.go

@@ -345,7 +345,7 @@ func calculateEtag(nodeID string, tmTime time.Time) (string, error) {
  } else {
  return "", err
  }
- return `"` + hex.EncodeToString(h.Sum(nil)) + `"`, nil
+ return fmt.Sprintf(`"%x"`, h.Sum(nil)), nil
 }
 
 // SetMtime sets the mtime and atime of a node