Don't report a PipeWire restart that didn't happen

[munzzyy]

audio-driver-restart.sh always reports the PipeWire restart as having worked:

systemctl --user restart pipewire pipewire-pulse wireplumber 2>/dev/null || true
sleep 1
log "PipeWire restarted"

The error goes to /dev/null, || true swallows the exit status, and the success line runs unconditionally.

That path can't really succeed as written. The script requires root at the top ([[ $EUID -ne 0 ]] && exit 1), and systemctl --user as root talks to root's own user manager, not the desktop user's session that owns the audio stack. So whoever runs this to fix a silent sound card is told PipeWire was restarted when nothing happened on the session that matters, and stops digging.

This keeps the behaviour non-fatal but stops it claiming success, and says why so the operator knows where to look. I left the actual user-session targeting alone on purpose — resolving the right uid (loginctl + runuser, or XDG_RUNTIME_DIR) is a design call, and I'd rather not guess at a convention for your test rigs. Happy to follow up with that if you want it.

The rebind logic above it is untouched.