ra_serf: Fix error leakage and improve error reporting.
ra_serf: Fix error leakage and improve error reporting.

* subversion/libsvn_ra_serf/getlocations.c
  (svn_ra_serf__get_locations): Return detailed error from server if
   available.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@866523 13f79535-47bb-0310-9956-ffa450edef68

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