rc: fixes systemd unit file stopping (#7157)
rc: fixes systemd unit file stopping (#7157)

In the ExecStopPost stanza of the unit file, an errant "}" made the lock
file never be deleted. Also the "-f" flag to rm always makes the
returncode 0 whether or not the file exists making the return code check
always return success.

Co-authored-by: Bryce Evans <cd7705dd26a434f0822911169275f3a001728a32@apple.com>
pbchou/trafficserver,duke8253/trafficserver,duke8253/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,SolidWallOfCode/trafficserver,duke8253/trafficserver,pbchou/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,duke8253/trafficserver,bryancall/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,vmamidi/trafficserver,SolidWallOfCode/trafficserver,bryancall/trafficserver,SolidWallOfCode/trafficserver,pbchou/trafficserver,pbchou/trafficserver,vmamidi/trafficserver,bryancall/trafficserver,bryancall/trafficserver,vmamidi/trafficserver,duke8253/trafficserver,vmamidi/trafficserver,duke8253/trafficserver,SolidWallOfCode/trafficserver