message: fix crash in pcm-latency when run as a non-root
  addresses issue reposted in
diff: @@ -3111,7 +3111,7 @@ void PCM::cleanupUncorePMUs()
  void PCM::resetPMU()
  {
  - for (int i = 0; i < (int)num_cores; ++i)
  + for (int i = 0; i < (int)MSR.size(); ++i)
  {
  // disable all counters
  MSR[i]->write(IA32_CR_PERF_GLOBAL_CTRL, 0);
  