message: nydusctl: print fs read errors and total read data
  It helps to analyz system performance
diff: @@ -296,6 +296,7 @@ impl CommandFsStats {
  let metrics = client.get("v1/metrics").await?;
  let m = metrics.as_object().unwrap();
  let fop_counter = m["fop_hits"].as_array().unwrap();
  + let fop_errors = m["fop_errors"].as_array().unwrap();
  if raw {
  println!("{}", metrics);
  } else {
  @@ -322,7 +323,15 @@ impl CommandFsStats {
  print!("{:<8}", d.as_u64().unwrap());
  }
  - println!();
  + println!("\n");
  +
  + println!("Read Errors: {}", fop_errors[4]);
  + let data_read = m["data_read"].as_u64().unwrap();
  + println!(
  + "Read Data: {}Bytes ({}MB)",
  + data_read,
  + data_read / 1024 / 1024
  + );
  print!(
  r#"
  