The OD_DERING_VERY_LARGE values are now explicitly copied to the buffer instead
of being read from the line buffer when we're on the edge of the frame. This
will make it possible to make the line buffer 8-bit for non-high-bitdepth.

No change in output

Change-Id: I1a4134d67ac7f8c239f08d73941405c56f01050b