Do not treat signaling and management messages as errors.

Instead we just ignore them for now.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

msg.c

@@ -188,6 +188,7 @@ int msg_post_recv(struct ptp_message *m, int cnt)
 		break;
 	case SIGNALING:
 	case MANAGEMENT:
+		break;
 	default:
 		return -1;
 	}