Moved ckp_runnig.txt to $LOGS (/p4/n/logs) from /p4/n/checkpoints:
* Avoids it getting rsync'd by sync_replica.sh or by common
human admin rsyncs of the /p4/n/checkpoints dir.
* It should be in a volume that's not shared.
* Puts it in the logs directory where you go look when things break.