syscalls.master where the file is generated from. Fix this by removing
it from syscalls.master so it doesn't come back.
From Nicolas Bedos.
-; $OpenBSD: syscalls.master,v 1.152 2015/02/09 13:54:23 deraadt Exp $
+; $OpenBSD: syscalls.master,v 1.153 2015/05/06 11:20:07 jsg Exp $
; $NetBSD: syscalls.master,v 1.32 1996/04/23 10:24:21 mycroft Exp $
; @(#)syscalls.master 8.2 (Berkeley) 1/13/94
#include <sys/mount.h>
#include <sys/syscallargs.h>
#include <sys/poll.h>
-#include <sys/event.h>
; Reserved/unimplemented system calls in the range 0-150 inclusive
; are reserved for use in future Berkeley releases.