fix memory leak in occlusion-filter
fix memory leak in occlusion-filter

* applies only to "vertical" orientations (i.e., L500 line)
* Tracked on RS5-7793

(cherry picked from commit ab483aa0a80d9045d613a827a27a7ab29723b899)

IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense,IntelRealSense/librealsense