test: avoid unused warning for test-display
test: avoid unused warning for test-display

meson -Dwith_x11=yes -Dwith_wayland=no -Dwith_drm=no -Dwith_egl=no
-Dwith_glx=no buildir

generate unused warnings.

ceyusa/gstreamer-vaapi,ceyusa/gstreamer-vaapi,GStreamer/gstreamer-vaapi,GStreamer/gstreamer-vaapi