DiscardRectangleCount must be less than or equal to
maxDiscardRectangles which is limited to 4.
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com> Reviewed-by: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16778>