Race condition during exit where RestrackThread can leave a mutex orphaned due to thread cancellation

[MarioHewardt]

Expected behavior

When running using -restrack, no error shown at the end of the run.

Actual behavior

Internal error displayed as a result of the RestrackTread being cancelled while waiting on the quit event which results in an orphaned mutex.

Steps to reproduce the behavior

1. sudo procdump -restrack

System information (e.g., distro, kernel version, etc.)

N/A