ne_xml_get_error

Recent versions of GCC warn about variables that are assigned but not
otherwise used. In libsvn_ra_neon we have:

../src/subversion/libsvn_ra_neon/lock.c:244:18: warning: variable ‘lck_parser’ set but not used
../src/subversion/libsvn_ra_neon/lock.c:510:18: warning: variable ‘lck_parser’ set but not used
../src/subversion/libsvn_ra_neon/util.c:1436:18: warning: variable ‘error_parser’ set but not used

These involve the creation of an ne_xml_parser. This prompted me to
look at other instances and the neon error handling is really
complicated. Some instances end up calling ne_get_xml_error but other
instances do not. Where ne_get_xml_error is called the order in which
things are done is not consistent.

In options.c:svn_ra_neon__exchange_capabilities the call is directly
after svn_ra_neon__request_dispatch, but in util.c:parsed_request if
parsing the spool file returns an error ne_get_xml_error is not
called, otherwise it is.

Should we always be calling ne_get_xml_error?

-- 
Philip