drm/udl: Don't track number of identical and sent pixels per line

A call to udl_render_hline() returns the number of identical and
sent pixels. None of these values is used. Remove the parameters.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191206085954.9697-3-tzimmermann@suse.de