[ipfw2] override errx() to prevent exit on error (#3840)

In ipfw2.c errx() would call exit(), aborting the UPF thread on rule parse
errors. Add a macro mapping errx() to ogs_log_message() so errors are logged.
We no longer call exit() and the main loop continues on error.

lib/ipfw/ipfw2.c

@@ -73,6 +73,10 @@ int resvd_set_number = RESVD_SET;
 
 int ipfw_socket = -1;
 
+#if 1 /* modifed by acetcom */
+#define errx(eval, ...) ogs_log_message(OGS_LOG_ERROR, 0, __VA_ARGS__)
+#endif
+
 #define	CHECK_LENGTH(v, len) do {				\
 	if ((v) < (len))					\
 		errx(EX_DATAERR, "Rule too long");		\