message: consistent use of error() message
  use error() when returning false rather than a LogPrintf followed by
  a return.  It looks better and uses one less line of code.
diff: @@ -6043,7 +6043,7 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, int64_t
  {
  LOCK(cs_main);
  Misbehaving(pfrom->GetId(), 100);
  - return false;
  + return error("Invalid xthinblock received");
  }
  // Send expedited block ASAP
  @@ -6078,7 +6078,7 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, int64_t
  {
  LOCK(cs_main);
  Misbehaving(pfrom->GetId(), 100);
  - return false;
  + return error("Invalid thinblock received");
  }
  CInv inv(MSG_BLOCK, thinBlock.header.GetHash());
  @@ -6100,10 +6100,9 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, int64_t
  // Message consistency checking
  if (thinRequestBlockTx.setCheapHashesToRequest.empty() || thinRequestBlockTx.blockhash.IsNull())
  {
  - LogPrintf("ERROR: incorrectly constructed get_xblocktx received. Banning peer=%d\n", pfrom->id);
  LOCK(cs_main);
  Misbehaving(pfrom->GetId(), 100);
  - return false;
  + return error("incorrectly constructed get_xblocktx received. Banning peer=%d\n", pfrom->id);
  }
  // We use MSG_TX here even though we refer to blockhash because we need to track
  @@ -6123,9 +6122,9 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, int64_t
  pfrom->nGetXBlockTxCount += 1;
  LogPrint("thin", "nGetXBlockTxCount is %f\n", pfrom->nGetXBlockTxCount);
  if (pfrom->nGetXBlockTxCount >= 20) {
  - LogPrintf("DOS: Misbehaving - requesting too many xblocktx: %s\n", inv.hash.ToString());
  LOCK(cs_main);
  Misbehaving(pfrom->GetId(), 100); // If they exceed the limit then disconnect them
  + return error("DOS: Misbehaving - requesting too many xblocktx: %s\n", inv.hash.ToString());
  }
  }
  @@ -6135,7 +6134,7 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, int64_t
  BlockMap::iterator mi = mapBlockIndex.find(inv.hash);
  if (mi == mapBlockIndex.end())
  {
  - LogPrint("thin", "Requested block is not available");
  + return error("Requested block is not available");
  }
  else
  {
  @@ -6143,7 +6142,7 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, int64_t
  const Consensus::Params& consensusParams = Params().GetConsensus();
  if (!ReadBlockFromDisk(block, (*mi).second, consensusParams))
  {
  - LogPrint("thin", "Cannot load block from disk -- Block txn request before assembled");
  + return error("Cannot load block from disk -- Block txn request before assembled");
  }
  else
  {
  @@ -6180,10 +6179,9 @@ bool ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, int64_t
  // Clear the thinblock timer used for preferential download
  thindata.ClearThinBlockTimer(inv.hash);
  - LogPrintf("ERROR: incorrectly constructed xblocktx or inconsistent thinblock data received. Banning peer=%d\n", pfrom->id);
  LOCK(cs_main);
  Misbehaving(pfrom->GetId(), 100);
  - return false;
  + return error("incorrectly constructed xblocktx or inconsistent thinblock data received. Banning peer=%d\n", pfrom->id);
  }
  LogPrint("net", "received blocktxs for %s peer=%d\n", inv.hash.ToString(), pfrom->id);
  