fixed memory leak in descriptor regression tests

modules/features2d/test/test_descriptors_regression.cpp

@@ -60,7 +60,7 @@ static void writeMatInBin( const Mat& mat, const string& filename )
         fwrite( (void*)&mat.rows, sizeof(int), 1, f );
         fwrite( (void*)&mat.cols, sizeof(int), 1, f );
         fwrite( (void*)&type, sizeof(int), 1, f );
-        int dataSize = (int)(mat.step * mat.rows * mat.channels());
+        int dataSize = (int)(mat.step * mat.rows);
         fwrite( (void*)&dataSize, sizeof(int), 1, f );
         fwrite( (void*)mat.ptr(), 1, dataSize, f );
         fclose(f);
@@ -82,13 +82,14 @@ static Mat readMatFromBin( const string& filename )
         int step = dataSize / rows / CV_ELEM_SIZE(type);
         CV_Assert(step >= cols);
 
-        Mat m = Mat(rows, step, type).colRange(0, cols);
+        Mat returnMat = Mat(rows, step, type).colRange(0, cols);
 
-        size_t elements_read = fread( m.ptr(), 1, dataSize, f );
+        size_t elements_read = fread( returnMat.ptr(), 1, dataSize, f );
         CV_Assert(elements_read == (size_t)(dataSize));
+
         fclose(f);
 
-        return m;
+        return returnMat;
     }
     return Mat();
 }