drm/vboxvideo: Don't set struct drm_driver.lastclose

Don't set struct drm_driver.lastclose. It's used to restore the
fbdev console. But as vboxvideo uses generic fbdev emulation, the
console is being restored by the DRM client helpers already. See
the call to drm_client_dev_restore() in drm_lastclose().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-4-tzimmermann@suse.de