message: Initialize nThreads in parallel.cpp
  Also, use nThreads.  The recent refactor was using nThreadCount rather
  than nThreads, which was a carry over and which is incorrect. This
  was causing PV->ThreadCount() to return with an incorrect value.
diff: @@ -38,7 +38,8 @@ static void AddScriptCheckThreads(int i, CCheckQueue<CScriptCheck> *pqueue)
  pqueue->Thread();
  }
  -CParallelValidation::CParallelValidation(boost::thread_group *threadGroup) : semThreadCount(nScriptCheckQueues)
  +CParallelValidation::CParallelValidation(boost::thread_group *threadGroup)
  + : nThreads(0), semThreadCount(nScriptCheckQueues)
  {
  // There are nScriptCheckQueues which are used to validate blocks in parallel. Each block
  // that validates will use one script check queue which must *not* be shared with any other
  @@ -48,22 +49,22 @@ CParallelValidation::CParallelValidation(boost::thread_group *threadGroup) : sem
  // Determine the number of threads to use for each check queue.
  //
  //-par=0 means autodetect number of cores.
  - int nThreadCount = GetArg("-par", DEFAULT_SCRIPTCHECK_THREADS);
  - if (nThreadCount <= 0)
  - nThreadCount += GetNumCores();
  + nThreads = GetArg("-par", DEFAULT_SCRIPTCHECK_THREADS);
  + if (nThreads <= 0)
  + nThreads += GetNumCores();
  // A single thread has no parallelism so just use the main thread
  // (Equivalent to parallel being turned off).
  - if (nThreadCount <= 1)
  - nThreadCount = 0;
  - else if (nThreadCount > MAX_SCRIPTCHECK_THREADS)
  - nThreadCount = MAX_SCRIPTCHECK_THREADS;
  + if (nThreads <= 1)
  + nThreads = 0;
  + else if (nThreads > MAX_SCRIPTCHECK_THREADS)
  + nThreads = MAX_SCRIPTCHECK_THREADS;
  // Create each script check queue with all associated threads.
  - LOGA("Launching %d ScriptQueues each using %d threads for script verification\n", nScriptCheckQueues, nThreadCount);
  + LOGA("Launching %d ScriptQueues each using %d threads for script verification\n", nScriptCheckQueues, nThreads);
  while (QueueCount() < nScriptCheckQueues)
  {
  auto queue = new CCheckQueue<CScriptCheck>(128);
  - for (int i = 0; i < nThreadCount; i++)
  + for (unsigned int i = 0; i < nThreads; i++)
  {
  threadGroup->create_thread(boost::bind(&AddScriptCheckThreads, i + 1, queue));
  }
  