fix breakage in in-kernel NAT: the code did not honor

net.inet.ip.fw.one_pass and always moved to the next rule
in case of a successful nat.

This should fix several related PR (waiting for feedback
before closing them)

PR:		145167 149572 150141
MFC after:	3 days

sys/netinet/ipfw/ip_fw_pfil.c

@@ -231,6 +231,11 @@ again:
 		break;
 
 	case IP_FW_NAT:
+		/* honor one-pass in case of successful nat */
+		if (V_fw_one_pass)
+			break; /* ret is already 0 */
+		goto again;
+
 	case IP_FW_REASS:
 		goto again;		/* continue with packet */