!8825 watchdog: Fix possible use-after-free in wdt_startup()

Merge Pull Request from: @ci-robot 
 
PR sync from: Zeng Heng <zengheng4@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/2NZC5YLOPSQ3KVUBSQGJCINHMD3GHK5E/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9ROH3 
 
Link:https://gitee.com/openeuler/kernel/pulls/8825

 

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