Put the call to notifier_call_chain() back in do_xenbus_probe().

This fixes some dom0 activities, such as ballooning, sysrqing,
and cpu hotplugging.
Signed-off-by: Dan Smith <danms@us.ibm.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>

linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c

@@ -627,6 +627,8 @@ int do_xenbus_probe(void *unused)
 	/* Watch for changes. */
 	register_xenbus_watch(&fe_watch);
 	register_xenbus_watch(&be_watch);
+	/* Notify others that xenstore is up */
+	notifier_call_chain(&xenstore_chain, 0, 0);
 	up(&xenbus_lock);
 	return 0;
 }