deadline-iosched.c: make a struct static

@@ -909,7 +909,7 @@
 	.store	= deadline_attr_store,
 };
 
-struct kobj_type deadline_ktype = {
+static struct kobj_type deadline_ktype = {
 	.sysfs_ops	= &deadline_sysfs_ops,
 	.default_attrs	= default_attrs,
 };