Fix for CUDA_Arithm/Dft.Algorithm/0 test

Author: nglee

modules/cudaarithm/test/test_arithm.cpp

@@ -253,7 +253,7 @@ CUDA_TEST_P(Dft, Algorithm)
     int cols = randomInt(2, 100);
     int rows = randomInt(2, 100);
 
-    int flags = 0;
+    int flags = 0 | DFT_COMPLEX_INPUT;
     cv::Ptr<cv::cuda::DFT> dft = cv::cuda::createDFT(cv::Size(cols, rows), flags);
 
     for (int i = 0; i < 5; ++i)