Make named_atomic-test find its sub-process under Windows, too.
Make named_atomic-test find its sub-process under Windows, too.

* subversion/tests/libsvn_subr/named_atomic-test.c
  (run_procs): add a bit of directory magic

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1326633 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion