Fix an arg for calcHist() in demos

`float* histRange = { range };` doesn't make much sense. `histRange` is
an array of array(s), so it should have a type of ptr to ptr. Strangely
some domos are correct as well as the example for the function
https://docs.opencv.org/master/d6/dc7/group__imgproc__hist.html#ga4b2b5fd75503ff9e6844cc4dcdaed35d

samples/cpp/tutorial_code/Histograms_Matching/MatchTemplate_Demo.cpp

@@ -89,7 +89,7 @@ void MatchingMethod( int, void* )
 
   //! [create_result_matrix]
   /// Create the result matrix
-  int result_cols =  img.cols - templ.cols + 1;
+  int result_cols = img.cols - templ.cols + 1;
   int result_rows = img.rows - templ.rows + 1;
 
   result.create( result_rows, result_cols, CV_32FC1 );