Revert small part of r22444.
Revert small part of r22444.

* subversion/tests/cmdline/update_tests.py
  (update_wc_on_windows_drive): splitfields() can only be called on string.

git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@862525 13f79535-47bb-0310-9956-ffa450edef68

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