Make gnome-power-backlight-helper do nothing and return 0 as it requires

the linux-only sysfs(2).

x11/gnome/power-manager/Makefile

@@ -1,10 +1,10 @@
-# $OpenBSD: Makefile,v 1.3 2011/05/24 10:41:58 ajacoutot Exp $
+# $OpenBSD: Makefile,v 1.4 2011/05/24 18:14:52 ajacoutot Exp $
 
 COMMENT=		GNOME power manager
 
 GNOME_PROJECT=		gnome-power-manager
 GNOME_VERSION=		2.32.0
-REVISION=		1
+REVISION=		2
 
 HOMEPAGE=		http://projects.gnome.org/gnome-power-manager/
 

x11/gnome/power-manager/patches/patch-src_gpm-backlight-helper_c

@@ -0,0 +1,24 @@
+$OpenBSD: patch-src_gpm-backlight-helper_c,v 1.1 2011/05/24 18:14:52 ajacoutot Exp $
+
+XXX make gnome-power-backlight-helper do nothing and return 0.
+
+--- src/gpm-backlight-helper.c.orig	Fri Aug  6 15:50:47 2010
++++ src/gpm-backlight-helper.c	Tue May 24 19:32:32 2011
+@@ -141,6 +141,7 @@ out:
+ gint
+ main (gint argc, gchar *argv[])
+ {
++#ifndef __OpenBSD__
+ 	GOptionContext *context;
+ 	gint uid;
+ 	gint euid;
+@@ -276,5 +277,9 @@ out:
+ 	g_free (filename_file);
+ 	g_free (contents);
+ 	return retval;
++#else
++	g_print ("This program does nothing on OpenBSD (no support for sysfs(2)).\n");
++	return 0;
++#endif
+ }
+