* Fixed OCL implementation of pyrlk
If prevPts size is (N, 1) (which is a default layout for converting `vector<Point2f>` to `UMat`) the `prevPts.cols == 1` and optical flow will be calculated for the first point only.
Getting `prevPts.total()` as in line 1048 is the correct way to get points count.
* fixed compilation warning (size_t to int)
Signed-off-by: Sergey Krivohatskiy <s.krivohatskiy@gmail.com>
af13f61a43