Mark a test that never passed for serf as XFail.
Mark a test that never passed for serf as XFail.

* subversion/tests/cmdline/switch_tests.py
  (forced_switch_failures,
   test_list): Mark forced_switch_failures as XFail for ra_serf.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@961773 13f79535-47bb-0310-9956-ffa450edef68

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