debugfs_lookup(): switch to lookup_one_len_unlocked()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/debugfs/inode.c

@@ -270,10 +270,7 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
 	if (!parent)
 		parent = debugfs_mount->mnt_root;
 
-	inode_lock(d_inode(parent));
-	dentry = lookup_one_len(name, parent, strlen(name));
-	inode_unlock(d_inode(parent));
-
+	dentry = lookup_one_len_unlocked(name, parent, strlen(name));
 	if (IS_ERR(dentry))
 		return NULL;
 	if (!d_really_is_positive(dentry)) {