Avoid leaking some errors.
Avoid leaking some errors.

* subversion/libsvn_ra_dav/fetch.c
  (add_props): Change return type to svn_error_t*, return errors from
   the setter function and set_special_wc_prop.
  (start_element, end_element): Return errors from editor prop changing
   functions.
  (add_node_props): Return error from add_props.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@852013 13f79535-47bb-0310-9956-ffa450edef68

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