message: fmt: ignore `log.*` fields when formatting events
  closes
diff: @@ -247,6 +247,9 @@ impl<'a> field::Visit for Recorder<'a> {
  self.maybe_pad();
  let _ = match field.name() {
  "message" => write!(self.writer, "{:?}", value),
  + // Skip fields that are actually log metadata that have already been handled
  + #[cfg(feature = "tracing-log")]
  + name if name.starts_with("log.") => Ok(()),
  name if name.starts_with("r#") => write!(self.writer, "{}={:?}", &name[2..], value),
  name => write!(self.writer, "{}={:?}", name, value),
  };
  