On svn-auth-x509 branch, Remove useless cast.

* subversion/libsvn_subr/x509parse.c
  (x509_name): You don't have to cast a void * to another pointer type.


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/svn-auth-x509@1619407 13f79535-47bb-0310-9956-ffa450edef68