Adding fixes in histogram test

Author: adsha-quic

modules/fastcv/perf/perf_histogram.cpp

@@ -23,7 +23,7 @@ PERF_TEST_P(HistogramPerfTest, run,
     cvtest::randUni(rng, src, Scalar::all(0), Scalar::all(255));
     Mat hist(1, 256, CV_32SC1);
 
-    for (;  next(); )
+    while (next())
     {
         startTimer();
         cv::fastcv::calcHist(src, hist);

modules/fastcv/src/histogram.cpp

@@ -63,7 +63,7 @@ void calcHist( InputArray _src, OutputArray _hist )
 
     cv::Mutex histogramLockInstance;
 
-    int nStripes = cv::getNumThreads();//(src.cols*src.rows)/(1<<8);
+    int nStripes = cv::getNumThreads();
     int stripeHeight = src.rows / nStripes;
 
     cv::parallel_for_(cv::Range(0, nStripes),