generated_serializer_test.cpp uses iostream without including it, relying on imports from another included header. Let's include iostream there. Signed-off-by: Milan Zamazal <mzamazal@redhat.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>