message: p2p: refactor: tidy up `PeerManagerImpl::Misbehaving(...)`
  introduce constant variables `score_before` and
  `score_after` in order to improve readability
  deduplicate calls to LogPrint(), eliminates else-branch
diff: @@ -1289,14 +1289,20 @@ void PeerManagerImpl::Misbehaving(const NodeId pnode, const int howmuch, const s
  if (peer == nullptr) return;
  LOCK(peer->m_misbehavior_mutex);
  + const int score_before{peer->m_misbehavior_score};
  peer->m_misbehavior_score += howmuch;
  + const int score_now{peer->m_misbehavior_score};
  +
  const std::string message_prefixed = message.empty() ? "" : (": " + message);
  - if (peer->m_misbehavior_score >= DISCOURAGEMENT_THRESHOLD && peer->m_misbehavior_score - howmuch < DISCOURAGEMENT_THRESHOLD) {
  - LogPrint(BCLog::NET, "Misbehaving: peer=%d (%d -> %d) DISCOURAGE THRESHOLD EXCEEDED%s\n", pnode, peer->m_misbehavior_score - howmuch, peer->m_misbehavior_score, message_prefixed);
  + std::string warning;
  +
  + if (score_now >= DISCOURAGEMENT_THRESHOLD && score_before < DISCOURAGEMENT_THRESHOLD) {
  + warning = " DISCOURAGE THRESHOLD EXCEEDED";
  peer->m_should_discourage = true;
  - } else {
  - LogPrint(BCLog::NET, "Misbehaving: peer=%d (%d -> %d)%s\n", pnode, peer->m_misbehavior_score - howmuch, peer->m_misbehavior_score, message_prefixed);
  }
  +
  + LogPrint(BCLog::NET, "Misbehaving: peer=%d (%d -> %d)%s%s\n",
  + pnode, score_before, score_now, warning, message_prefixed);
  }
  bool PeerManagerImpl::MaybePunishNodeForBlock(NodeId nodeid, const BlockValidationState& state,
  