!1906 tracing: Fix memleak due to race between current_tracer and trace

Merge Pull Request from: @ci-robot 
 
PR sync from: Zheng Yejian <zhengyejian1@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/IQOGRJ2SSD7QYTDDRIE5DYFGH4YEGZXD/ 
 
https://gitee.com/openeuler/kernel/issues/I7WMCI 
 
Link:https://gitee.com/openeuler/kernel/pulls/1906

 

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