Fix SEGFAULT introduced in r32545.
Fix SEGFAULT introduced in r32545.

* subversion/libsvn_fs_fs/tree.c
  (fs_node_origin_rev): Avoid dup'ing a NULL pointer.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion