compositor-drm: Reshuffle drm_output_render

Call drm_output_render unconditionally, doing an early exit if we're
already rendering a client buffer on the primary plane.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
1 file changed