message: Remove length check in output_pkt_for_path()
  All the other length checks are grouped at the top, and this one should
  be extraneous given the other checks.
diff: @@ -1147,7 +1147,10 @@ impl Connection {
  loop {
  let used =
  out_bytes.len() + encoder.len() + hdr.overhead(&tx.aead, path.mtu());
  - let remaining = min(path.mtu() - used, cong_avail.saturating_sub(used));
  + let remaining = min(
  + path.mtu().saturating_sub(used),
  + cong_avail.saturating_sub(used),
  + );
  if remaining < 2 {
  // All useful frames are at least 2 bytes.
  break;
  @@ -1259,9 +1262,6 @@ impl Connection {
  dump_packet(self, "TX ->", &hdr, &encoder);
  out_bytes.append(&mut packet);
  - if out_bytes.len() >= path.mtu() {
  - break;
  - }
  }
  if close_sent {
  