vmm node only needs mode 600

src/etc/MAKEDEV.common

@@ -1,4 +1,4 @@
-vers(a, {-$OpenBSD: MAKEDEV.common,v 1.81 2015/11/10 21:49:18 sthen Exp $-})dnl
+vers(a, {-$OpenBSD: MAKEDEV.common,v 1.82 2015/12/09 04:11:58 deraadt Exp $-})dnl
 dnl
 dnl Copyright (c) 2001-2006 Todd T. Fries <todd@OpenBSD.org>
 dnl
@@ -524,5 +524,5 @@ _mkdev(hotplug, hotplug, {-M hotplug c major_hotplug_c $U 400-})dnl
 __devitem(gpio, gpio*, General Purpose Input/Output)dnl
 _mcdev(gpio, gpio*, gpio, {-major_gpio_c-}, 600)dnl
 __devitem(vmm, vmm, Virtual Machine Monitor)dnl
-_mkdev(vmm, vmm, {-M vmm c major_vmm_c 0 640-})dnl
+_mkdev(vmm, vmm, {-M vmm c major_vmm_c 0 600-})dnl
 _mkdev(local, local, {-test -s $T.local && sh $T.local-})dnl