message: Fix integer overflow when accumulating timing values.
diff: @@ -3074,7 +3074,7 @@ void Net::setHalideScheduler(const String& scheduler)
  int64 Net::getPerfProfile(std::vector<double>& timings)
  {
  timings = std::vector<double>(impl->layersTimings.begin() + 1, impl->layersTimings.end());
  - int64 total = std::accumulate(timings.begin(), timings.end(), 0);
  + int64 total = (int64)std::accumulate(timings.begin(), timings.end(), 0.0);
  return total;
  }
  