xen: use static initializers in xen-balloon.c

There is no need to use dynamic initializaion, it just confuses the reader.
Switch to static initializers like its used in other files.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
[v2: Rebased on v3.0]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/xen-balloon.c

@@ -50,11 +50,6 @@ static struct sys_device balloon_sysdev;
 
 static int register_balloon(struct sys_device *sysdev);
 
-static struct xenbus_watch target_watch =
-{
-	.node = "memory/target"
-};
-
 /* React to a change in the target key */
 static void watch_target(struct xenbus_watch *watch,
 			 const char **vec, unsigned int len)
@@ -73,6 +68,11 @@ static void watch_target(struct xenbus_watch *watch,
 	 */
 	balloon_set_new_target(new_target >> (PAGE_SHIFT - 10));
 }
+static struct xenbus_watch target_watch = {
+	.node = "memory/target",
+	.callback = watch_target,
+};
+
 
 static int balloon_init_watcher(struct notifier_block *notifier,
 				unsigned long event,
@@ -87,7 +87,9 @@ static int balloon_init_watcher(struct notifier_block *notifier,
 	return NOTIFY_DONE;
 }
 
-static struct notifier_block xenstore_notifier;
+static struct notifier_block xenstore_notifier = {
+	.notifier_call = balloon_init_watcher,
+};
 
 static int __init balloon_init(void)
 {
@@ -100,9 +102,6 @@ static int __init balloon_init(void)
 
 	register_xen_selfballooning(&balloon_sysdev);
 
-	target_watch.callback = watch_target;
-	xenstore_notifier.notifier_call = balloon_init_watcher;
-
 	register_xenstore_notifier(&xenstore_notifier);
 
 	return 0;