drm: logicvc: fix error code in logicvc_layer_init()

Return -EINVAL if logicvc_layer_formats_lookup() fails.  Don't return
success.

Fixes: efeeaefe

 ("drm: Add support for the LogiCVC display controller")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/Yqh6VdNiDvJYMOQ+@kili