The call to ff_exp2fi() here always uses arguments in the normal
range, so that the branches in ff_exp2fi() are unnecessary.
This is so because JPEG2000 itself only supports up to
128 bits per component per pixel (we only support far less);
furthermore, expn is always 0..31 for the decoder and also
sane for the encoder, so that the difference between these
two values is always in the normal range of -126..128.
Reviewed-by: Tomas Härdin <git@haerdin.se>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>