(cherry pick from commit c18c2130d0)
- Check if the result of opendir is NULL in lastLogTime
- Cleanup: alphabetically sorted long options, reserved
an alias for --regex
- Add a unit test, non existent directory should return
gracefully with an exit(1) and not SIGSEGV.
NB: This failure was with eng/debug feature logpersist
turned on, /data/misc/logd/ directory was missing,
deleted, or temporarily inaccessible.
Bug: 27954627
Change-Id: I60246a53b02fdd7e5490fe458b02ad7b14843584