Motivated by an oversight of mine when looking at the atomic bochs
conversion. For consistency also switch over to the same style as used
elsewhere (e.g. in drm_mode_set_config_internal).

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Noralf Trønnes <noralf@tronnes.org>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190110103045.26821-1-daniel.vetter@ffwll.ch