fix bogus path_put() of nd->root after some unlazy_walk() failures

Failure to grab reference to parent dentry should go through the
same cleanup as nd->seq mismatch. As it is, we might end up with
caller thinking it needs to path_put() nd->root, with obvious
nasty results once we'd hit that bug enough times to drive the
refcount of root dentry all the way to zero...

Signed-off-by: Al Viro <[e-mail]>

fs/namei.c

···
 
 	if (!lockref_get_not_dead(&parent->d_lockref)) {
 		nd->path.dentry = NULL;	
-		rcu_read_unlock();
-		return -ECHILD;
+		goto out;
 	}
 
 	/*