bcachefs: fix new reinherit_attrs ioctl

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/fs-ioctl.c

@@ -184,7 +184,7 @@ static int bch2_ioc_reinherit_attrs(struct bch_fs *c,
 	if (unlikely(ret < 0))
 		goto err1;
 
-	qstr.hash_len	= ret;
+	qstr.len	= ret;
 	qstr.name	= kname;
 
 	ret = -ENOENT;