message: Fix blocking desc usage
diff: @@ -130,9 +130,8 @@ inline IE::TensorDesc toIE(const cv::Mat &mat, cv::gapi::ie::TraitAs hint) {
  const size_t height = mat.size().height;
  const size_t width = mat.size().width;
  - const size_t strideH = mat.step[0];
  -
  - IE::BlockingDesc bdesc({1, height, width, channels} /* dims */,
  + const size_t strideH = mat.step1();
  + IE::BlockingDesc bdesc({1, channels, height, width} /* dims */,
  {0, 2, 3, 1} /* order for NHWC */,
  0 /* offset */,
  {0, 0, 0, 0} /* offsets for dims */,
  