!7840 netrom: Fix a data-race around sysctl_netrom_transport_timeout

Merge Pull Request from: @ci-robot 
 
PR sync from: Hui Tang <tanghui20@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/C6FVPUL6UZLY4BUKZNIH4NGTVNMVIRDT/ 
 
https://gitee.com/src-openeuler/kernel/issues/I9Q95M 
 
Link:https://gitee.com/openeuler/kernel/pulls/7840

 

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