Don't wait to remove bad lock

This will significantly shorten the window for the race condition where process 1 detects an invalid lock, but process 2 gets a valid lock before process 1 can remove the invalid lock.  Process 1 didn't check to make sure the lock was still invalid, so it mistakenly removed process 2's valid lock.
The race condition still exists, but the window is a few milliseconds rather than 1 hr.