rocknix: runemu.sh returns how the launch ended

[maxengel]

What

wait_lock() in profile.d/001-functions installs

trap 'rm -f "$lockfile"; exit $?' INT TERM EXIT

On EXIT the trap runs rm (status 0) and then re-exits with rm's status, so every script that has taken the settings lock exits 0 however it ended. runemu.sh takes it (cooling profile, netplay mode), so its quit 1 after a failed launch reaches EmulationStation as 0 — a RetroArch Failed to load content looked like a clean exit. $lockfile is also never assigned anywhere, so the trap never removed the lock it was there to release: a script killed while holding it left /tmp/.system.cfg.lock behind and later set_setting calls spun forever.

Fix

• Save $? first and exit with it. Name the lock (J_CONF_LOCK) and remove it only when this shell still owns it: every caller releases the lock itself a few lines after taking it, the trap stays installed for the rest of the shell's life, and by the time a long-lived script like runemu.sh exits another process may hold the file. The EXIT arm stays for callers under set -e, where a failed sed inside del_setting exits with the lock held.
• With the status reported for the first time, an emulator ended by the global exit hotkey (killall -9 → 137, SIGTERM → 143) would read as a failed launch — EmulationStation records play count and last-played only on 0. runemu.sh maps 137 and 143 to 0 with a log line; every other non-zero status still collapses to 1, leaving 200–300 for the messages EmulationStation can name.

Testing

On a GENERIC_X64 build: with a 64 KiB zero ROM, runemu.sh logged exiting with 1 and returned 0 before, 1 after; exit 7 while holding the lock returns 7 and releases it; a lock another pid owns at exit is left alone; TERM while holding returns 143 and releases it; set -e with a failed sed in del_setting returns 1 and releases the lock (was 0 with the lock left behind); a live RetroArch ended with SIGKILL returns 0. The same failed launch, driven through EmulationStation, reached the post-launch step as exit 1. Also running on two Anbernic H700 handhelds.

Known edge, left as is: RetroArch force-quit by the hotkey's SIGTERM exits 1 on its own, indistinguishable from a failed load.

No user-facing option or documentation changes.