the lex code in heimdal had a function error_message() which is
confusingly the ame as a core function from the com_err library. This
replaces it with lex_error_message(), and allows Samba4 to have a
stricter check for duplicate symbols between it's components.
Pair-Programmed-With: Andrew Tridgell <tridge@samba.org>
Signed-off-by: Love Hornquist Astrand <lha@h5l.org>