trivial: Remove "vif" script

'xen/vif-openstack' is a script for configuring a Xen VIF in bridge
mode. This script duplicates functionality now provided in Xen itself
and does not need to remain in the nova codebase.

[1] https://xenbits.xen.org/gitweb/?p=xen.git;f=tools/hotplug/Linux/vif-bridge;h=3d72ca4

Change-Id: Iafacfdfb96f78c3f1682139892fdcca3616b6cab
TrivialFix

contrib/xen/vif-openstack

@@ -1,38 +0,0 @@
-#!/bin/bash
-
-## copyright: B1 Systems GmbH <info@b1-systems.de>, 2012.
-## author: Christian Berendt <berendt@b1-systems.de>, 2012.
-## license: Apache License, Version 2.0
-##
-## purpose:
-##   Creates a new vif device without attaching it to a
-##   bridge. Neutron Linux Bridge Agent will attach the
-##   created device to the belonging bridge.
-##
-## usage:
-##   place the script in ${XEN_SCRIPT_DIR}/vif-openstack and
-##   set (vif-script vif-openstack) in /etc/xen/xend-config.sxp.
-
-dir=$(dirname "$0")
-. "$dir/vif-common.sh"
-
-case "$command" in
-    online)
-        setup_virtual_bridge_port "$dev"
-        ip link set $dev up
-        ;;
-
-    offline)
-        ip link set $dev down
-        ;;
-
-    add)
-        setup_virtual_bridge_port "$dev"
-        ip link set $dev up
-        ;;
-esac
-
-if [ "$type_if" = vif -a "$command" = "online" ]
-then
-  success
-fi