Fix davautocheck.sh for VPATH builds with a single test (i.e. 'davautocheck.sh basic').
Fix davautocheck.sh for VPATH builds with a single test (i.e. 'davautocheck.sh
basic').

* subversion/tests/cmdline/davautocheck.sh
  (main): Refer to the test directory explicitly instead of assuming that
  ABS_BUILDDIR is equal to the SCRIPTDIR.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@862253 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion