Fix XFailing merge_tests.py 90 'merge added subtree'.  It still fails, but  now fails for the "right" reason.
Fix XFailing merge_tests.py 90 'merge added subtree'.  It still fails, but 
now fails for the "right" reason.

This is the test for issue #1962.

* subversion/tests/cmdline/merge_tests.py
  (merge_added_subtree): Since r28802 svntest.tree.compare_trees() takes
  a label as the first argument.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@871662 13f79535-47bb-0310-9956-ffa450edef68

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