$NetBSD: patch-ax,v 1.2 2015/12/29 23:34:52 dholland Exp $

Use standard headers.

--- mpdm/filter.c.orig	2005-03-01 16:26:14.000000000 +0000
+++ mpdm/filter.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <unistd.h>
 #include "../gen.h"
 #include "../util.h"