!4068 mm/oom_kill: fix NULL pointer dereference in memcg_print_bad_task()

Merge Pull Request from: @ci-robot 
 
PR sync from: Jinjiang Tu <tujinjiang@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/DL2SF3GV5CACUT7XPM7PP24RKCOTCOJF/ 
 
https://gitee.com/openeuler/kernel/issues/I8WVL2 
 
Link:https://gitee.com/openeuler/kernel/pulls/4068

 

Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>