xen: Rename xen_be_unbind_evtchn

Prepare xen_be_unbind_evtchn to be shared with frontends:
 * xen_be_unbind_evtchn -> xen_pv_unbind_evtchn

Signed-off-by: Emil Condrea <emilcondrea@gmail.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Quan Xu <xuquan8@huawei.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
diff --git a/hw/net/xen_nic.c b/hw/net/xen_nic.c
index 2d6e033..c996684 100644
--- a/hw/net/xen_nic.c
+++ b/hw/net/xen_nic.c
@@ -372,7 +372,7 @@
 {
     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev);
 
-    xen_be_unbind_evtchn(&netdev->xendev);
+    xen_pv_unbind_evtchn(&netdev->xendev);
 
     if (netdev->txs) {
         xengnttab_unmap(netdev->xendev.gnttabdev, netdev->txs, 1);