On svn-auth-x509 branch, Add some code to debug Windows temporarily.

* subversion/libsvn_subr/x509parse.c
  (x509name_to_utf8_string): Use the string to show an error code.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/svn-auth-x509@1612976 13f79535-47bb-0310-9956-ffa450edef68