Audit path too long errror. Add comments about non-audit events

and placeholders for future audit hooks.

plugins/sudoers/env.c

@@ -1010,6 +1010,7 @@ validate_env_vars(char * const env_vars[])
     }
     if (bad != NULL) {
 	bad[blen - 2] = '\0';		/* remove trailing ", " */
+	/* XXX - audit? */
 	log_fatal(NO_MAIL,
 	    N_("sorry, you are not allowed to set the following environment variables: %s"), bad);
 	/* NOTREACHED */