build fix

samples/cpp/tutorial_code/ImgTrans/HoughCircle_Demo.cpp

@@ -28,7 +28,7 @@ namespace
         // will hold the results of the detection
         std::vector<Vec3f> circles;
         // runs the actual detection
-        HoughCircles( src_gray, circles, HOUGH_GRADIENT, 1, src_gray.rows/8, cannyThreshold, accumulatorThreshold, 0, 0 );
+        HoughCircles( src_gray, circles, CV_HOUGH_GRADIENT, 1, src_gray.rows/8, cannyThreshold, accumulatorThreshold, 0, 0 );
 
         // clone the colour, input image for displaying purposes
         Mat display = src_display.clone();