message: [scmd] fix scmd error help message display.
diff: @@ -34,11 +34,12 @@ pub fn print_action_result(format: OutputFormat, result: Result<Value>) -> Resul
  print_json(value)
  }
  OutputFormat::TABLE => {
  - let value = match result {
  - Ok(value) => value,
  - Err(err) => json!({"err": err.to_string()}),
  + match result {
  + Ok(value) => print_table(value)?,
  + // err may contains help message, so directly print err.
  + Err(err) => println!("{}", err.to_string()),
  };
  - print_table(value)
  + Ok(())
  }
  }
  }
  