No need for crossing to mountpoint in audit_tag_tree()

is_under() will DTRT anyway.  And yes, is_subdir() behaviour
is intentional.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/dcache.c

@@ -2149,7 +2149,6 @@ int is_subdir(struct dentry *new_dentry, struct dentry *old_dentry)
 	int result;
 	unsigned long seq;
 
-	/* FIXME: This is old behavior, needed? Please check callers. */
 	if (new_dentry == old_dentry)
 		return 1;
 

kernel/audit_tree.c

@@ -734,9 +734,6 @@ int audit_tag_tree(char *old, char *new)
 	dentry = dget(path.dentry);
 	path_put(&path);
 
-	if (dentry == tagged->mnt_root && dentry == mnt->mnt_root)
-		follow_up(&mnt, &dentry);
-
 	list_add_tail(&list, &tagged->mnt_list);
 
 	mutex_lock(&audit_filter_mutex);