message: ts: fix perf calibation
  properly handle "check" mode with:
  "--perf_min_samples=1 --perf_force_samples=1"
diff: @@ -25,7 +25,7 @@ using namespace cvtest;
  using namespace perf;
  int64 TestBase::timeLimitDefault = 0;
  -unsigned int TestBase::iterationsLimitDefault = (unsigned int)(-1);
  +unsigned int TestBase::iterationsLimitDefault = UINT_MAX;
  int64 TestBase::_timeadjustment = 0;
  // Item [0] will be considered the default implementation.
  @@ -1158,7 +1158,7 @@ void TestBase::Init(const std::vector<std::string> & availableImpls,
  }
  timeLimitDefault = param_time_limit == 0.0 ? 1 : (int64)(param_time_limit * cv::getTickFrequency());
  - iterationsLimitDefault = param_force_samples == 0 ? (unsigned)(-1) : param_force_samples;
  + iterationsLimitDefault = param_force_samples == 0 ? UINT_MAX : param_force_samples;
  _timeadjustment = _calibrate();
  }
  @@ -1197,9 +1197,13 @@ enum PERF_STRATEGY TestBase::getCurrentModulePerformanceStrategy()
  int64 TestBase::_calibrate()
  {
  CV_TRACE_FUNCTION();
  + if (iterationsLimitDefault <= 1)
  + return 0;
  +
  class _helper : public ::perf::TestBase
  {
  public:
  + _helper() { testStrategy = PERF_STRATEGY_BASE; }
  performance_metrics& getMetrics() { return calcMetrics(); }
  virtual void TestBody() {}
  virtual void PerfTestBody()
  @@ -1210,13 +1214,17 @@ int64 TestBase::_calibrate()
  cv::Mat b(2048, 2048, CV_32S, cv::Scalar(2));
  declare.time(30);
  double s = 0;
  - for(declare.iterations(20); next() && startTimer(); stopTimer())
  + declare.iterations(20);
  + minIters = nIters = 20;
  + for(; next() && startTimer(); stopTimer())
  s+=a.dot(b);
  declare.time(s);
  //self calibration
  SetUp();
  - for(declare.iterations(1000); next() && startTimer(); stopTimer()){}
  + declare.iterations(1000);
  + minIters = nIters = 1000;
  + for(int iters = 0; next() && startTimer(); iters++, stopTimer()) { /*std::cout << iters << nIters << std::endl;*/ }
  }
  };
  