message: ts(perf): initialize ThreadPool
diff: @@ -1212,6 +1212,18 @@ int64 TestBase::_calibrate()
  }
  };
  + // Initialize ThreadPool
  + class _dummyParallel : public ParallelLoopBody
  + {
  + public:
  + void operator()(const cv::Range& range) const
  + {
  + // nothing
  + CV_UNUSED(range);
  + }
  + };
  + parallel_for_(cv::Range(0, 1000), _dummyParallel());
  +
  _timeadjustment = 0;
  _helper h;
  h.PerfTestBody();
  @@ -1838,6 +1850,8 @@ void TestBase::SetUp()
  if (param_threads >= 0)
  cv::setNumThreads(param_threads);
  + else
  + cv::setNumThreads(-1);
  #ifdef __ANDROID__
  if (param_affinity_mask)
  