!9058 watchdog: Fix possible use-after-free by calling del_timer_sync()

Merge Pull Request from: @ci-robot 
 
PR sync from: Jialin Zhang <zhangjialin11@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/D32MYLOO7ACQMGDUQEHZM52LYV4RWTQZ/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9RL1P 
 
Link:https://gitee.com/openeuler/kernel/pulls/9058

 

Reviewed-by: Liu YongQiang <liuyongqiang13@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>