mediafoundation: on use LTR, synchronize the active ltr bitmap to the one passed in

Reviewed-by: Yubo Xie <yuboxie@microsoft.com>
Reviewed-by: Sil Vilerino <sivileri@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35219>

src/gallium/frontends/mediafoundation/reference_frames_tracker_hevc.cpp

@@ -153,6 +153,8 @@ reference_frames_tracker_hevc::begin_frame( reference_frames_tracker_dpb_async_t
                ++itr;
             }
          }
+
+         m_ActiveLTRBitmap = useLTRBitmap & 0xFFFF; // synchronize active LTR bitmap with useLTRBitmap
       }
 
       ltrUsedBitMask = PrepareFrameRefLists();