Xen: fix cpu_hotplug.c build by replacing is_running_on_xen() with xen_pv_domain()

Signed-off-by: NAlex Nixon <alex.nixon@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

drivers/xen/cpu_hotplug.c

@@ -78,7 +78,7 @@ static int __init setup_vcpu_hotplug_event(void)
 	static struct notifier_block xsn_cpu = {
 		.notifier_call = setup_cpu_watcher };
 
-	if (!is_running_on_xen())
+	if (!xen_pv_domain())
 		return -ENODEV;
 
 	register_xenstore_notifier(&xsn_cpu);