Fix the segfault/assertion uncovered in r1455881.

* subversion/libsvn_wc/wc_db_update_move.c
  (mark_tree_conflict): Handle no origin as unversioned.

* subversion/tests/libsvn_wc/op-depth-test.c
  (test_funcs): Remove XFail marker.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1455908 13f79535-47bb-0310-9956-ffa450edef68