Fix the bug for feature_score computation
Fix the bug for feature_score computation

The visited is not set to 1 after an item is pushed into the heap.
This may cause one item being pushed into the heap multiple
times, which may incur buffer overflow and memory corruption.

Change-Id: I443f1e5693856bb4066542403f98492d4daec69d

webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx