samples: use findFile() in "cpp"

samples/cpp/points_classifier.cpp

@@ -2,11 +2,6 @@
 #include "opencv2/imgproc.hpp"
 #include "opencv2/ml.hpp"
 #include "opencv2/highgui.hpp"
-#ifdef HAVE_OPENCV_OCL
-#define _OCL_KNN_ 1 // select whether using ocl::KNN method or not, default is using
-#define _OCL_SVM_ 1 // select whether using ocl::svm method or not, default is using
-#include "opencv2/ocl/ocl.hpp"
-#endif
 
 #include <stdio.h>