!1472 ipv6/addrconf: fix a potential refcount underflow for idev

Merge Pull Request from: @ci-robot 
 
PR sync from: Ziyang Xuan <william.xuanziyang@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/DIK47VH6DI376MCBPUDGF7OCT76C4BMQ/ 
 
https://gitee.com/openeuler/kernel/issues/I7M991 
 
Link:https://gitee.com/openeuler/kernel/pulls/1472

 

Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Liu YongQiang <liuyongqiang13@huawei.com>