net/9p: add __init/__exit annotations to module init/exit funcs

xen transport was missing annotations

Link: https://lkml.kernel.org/r/20220909103546.73015-1-xiujianfeng@huawei.com
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

net/9p/trans_xen.c

@@ -511,7 +511,7 @@ static struct xenbus_driver xen_9pfs_front_driver = {
 	.otherend_changed = xen_9pfs_front_changed,
 };
 
-static int p9_trans_xen_init(void)
+static int __init p9_trans_xen_init(void)
 {
 	int rc;
 
@@ -530,7 +530,7 @@ static int p9_trans_xen_init(void)
 module_init(p9_trans_xen_init);
 MODULE_ALIAS_9P("xen");
 
-static void p9_trans_xen_exit(void)
+static void __exit p9_trans_xen_exit(void)
 {
 	v9fs_unregister_trans(&p9_xen_trans);
 	return xenbus_unregister_driver(&xen_9pfs_front_driver);