[LTP] [PATCH] Add ltp pivot_root test

[Cyril Hrubis]

Hi!
Pushed with minor changes, thanks.

* Added .gitignore for the pivot_root01 binary

* Changed tst_brk(TFAIL, ...) to tst_brk(TBROK, ...)
  (see https://github.com/linux-test-project/ltp/issues/462)

* Made use of TERRNO flag instead of strerror(), we avoid using
  strerror() since it produces localized sentencies instead of
  errno symbolic names. Instead we use either TERRNO or tst_strerrno()
  function.

-- 
Cyril Hrubis
chrubis@suse.cz