Simplify some tree conflict code by removing an (unused) error return.
Simplify some tree conflict code by removing an (unused) error return.

* subversion/libsvn_wc/tree_conflicts.c:
  (skel_prepend_enum): remove error return. never used.
  (prepend_version_info, svn_wc_serialize_conflict): adjust calls to
    skel_prepend_enum().


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@1100460 13f79535-47bb-0310-9956-ffa450edef68

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