shfl_scan 's shuffle_integral_image_test has some misleading code.

[zhou3968322]

cuda-samples/Samples/2_Concepts_and_Techniques/shfl_scan/shfl_scan.cu

Lines 329 to 333 in 5f97d7d

	checkCudaErrors(cudaMalloc(reinterpret_cast<void **>(&d_data), sz));
	checkCudaErrors(cudaMalloc(reinterpret_cast<void **>(&d_integral_image),
	n_elements * sizeof(int) * 4));
	checkCudaErrors(cudaMemset(d_data, 1, sz));
	checkCudaErrors(cudaMemset(d_integral_image, 0, sz));

The size of d_data and d_integral_image here can be misleading.

  int n_elements = w * h;
  int sz = sizeof(unsigned int) * n_elements;
  checkCudaErrors(cudaMallocHost(reinterpret_cast<void **>(&h_image), sz));
  
  
  checkCudaErrors(cudaMalloc(reinterpret_cast<void **>(&d_data), sz));
  checkCudaErrors(cudaMalloc(reinterpret_cast<void **>(&d_integral_image),
                             n_elements * sizeof(int) * 4));
  checkCudaErrors(cudaMemset(d_data, 1, sz));
  checkCudaErrors(cudaMemset(d_integral_image, 0, sz));

d_data 's size is (w * h) *sizeof(char) in this ap, while malloc it with w * h *sizeof(unsigned int).
d_integral_image's size is n_elements * sizeof(int) in this ap.
Current version has a puzzling size.

change it to:

  int n_elements = w * h;
  int sz = sizeof(unsigned int) * n_elements;
  checkCudaErrors(cudaMallocHost(reinterpret_cast<void **>(&h_image), sz));
  
  
  checkCudaErrors(cudaMalloc(reinterpret_cast<void **>(&d_data), sz / 4));
  checkCudaErrors(cudaMalloc(reinterpret_cast<void **>(&d_integral_image),
                             n_elements * sizeof(int)));
  checkCudaErrors(cudaMemset(d_data, 1, sz / 4));
  checkCudaErrors(cudaMemset(d_integral_image, 0, sz));

may be better?