!1346 dm thin metadata: check fail_io before using data_sm

Merge Pull Request from: @ci-robot 
 
PR sync from: Li Lingfeng <lilingfeng3@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/GPIRJFVX4XM2YVPZLAGHIGOXHIEMS2DK/ 
 
 
Link:https://gitee.com/openeuler/kernel/pulls/1346

 

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>