iokitd opens DISPLAY and falls back to :0, but the env-check probe only asked
xdpyinfo for DISPLAY. It could warn on a host where iokitd still had a display,
or pass on :0 while DISPLAY was broken. The probe now tries :0 when DISPLAY is
unset or cannot be opened, and the one-line log names the fallback, so the
probe and the guest agree.
prepare.py --check-only validates all 31 patch entries with the new hunk;
iokitd rebuilds and carries the new message.
Signed-off-by: zero <zero@localhost>
zero
33a5c48656