Since we are clipping before we shift the values to
16 or 32 bits, we should not shift the min/max clip
values to compensate.

Fixes 8 and 24 bit lossy decoding.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>