switch mnt_namespace ->root to struct mount

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/mount.h b/fs/mount.h
index c6e99e0..0921b51 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -4,7 +4,7 @@
 
 struct mnt_namespace {
 	atomic_t		count;
-	struct vfsmount *	root;
+	struct mount *	root;
 	struct list_head	list;
 	wait_queue_head_t poll;
 	int event;