radv: fix wide points and lines

The maximum value for both points and lines is 65536. This doesn't
fix anything known (just found this while looking in that area).

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5696>
3 files changed