!5528 btrfs: do not BUG_ON in link_to_fixup_dir

Merge Pull Request from: @ci-robot 
 
PR sync from: Zhihao Cheng <chengzhihao1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/SG4M5HMKWOYPY6MSZTAYVSTOURCENOHK/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9BGQL 
 
Link:https://gitee.com/openeuler/kernel/pulls/5528

 

Reviewed-by: Liu YongQiang <liuyongqiang13@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>