[PATCH] [sanitizer] Fix log_path behavior with StopTheWorld.

[Alexey Samsonov]

  Then I think we should make both parent process and tracer task write into the same file. Tracer task is an implementation detail, not some actual subprocess started by the user program, why we should open a new file for it? Consider you ran StopTheWorld for a single application 1000 times in a row with logging, I doubt you'd want to see 1000 files in your directory.

http://llvm-reviews.chandlerc.com/D2306