avcodec/cavsdec, h264*, hevc_parser: Use get_ue_golomb_31 where possible

avcodec/cavsdec, h264*, hevc_parser: Use get_ue_golomb_31 where possible

instead of get_ue_golomb(). The difference between the two is that the
latter also has to take into account the case in which the read code is
more than 9 bits (four preceding zeroes + at most five value bits) long,
leading to more code.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>