The location where a node is moved to is always an operation root, so remove
dead code for when that wouldn't be the case.

* subversion/libsvn_wc/wc_db_update_move.c
  (break_move): Calculate destination depth and use a more optimal query
    to clear moved here status.
  (svn_wc__db_resolve_break_moved_away_internal,
   break_moved_away_children_internal): Update callers.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1538699 13f79535-47bb-0310-9956-ffa450edef68