maint: add omitted copyright header

Bug introduced in commit 6a597883.

* src/util/netlink.h: Add boilerplate.

src/util/netlink.h

+/*
+ * Copyright (C) 2010-2011 Red Hat, Inc.
+ * Copyright (C) 2010 IBM Corporation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
+ */
+
 #ifndef __VIR_NETLINK_H__
 # define __VIR_NETLINK_H__