alinux: mm, memcg: abort priority oom if with oom victim

Explicitly abort mem_cgroup_select_bad_process in priority oom if there
is already a task as oom victim without MMF_OOM_SKIP flag set.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>

mm/memcontrol.c

@@ -1266,6 +1266,8 @@ void mem_cgroup_select_bad_process(struct oom_control *oc)
 	mem_cgroup_scan_tasks(victim, oom_evaluate_task, oc);
 	if (oc->use_priority_oom) {
 		css_put(&victim->css);
+		if (oc->chosen == (void *)-1UL)
+			goto out;
 		if (!oc->chosen && victim != memcg) {
 			do_mem_cgroup_account_oom_skip(victim, oc);
 			goto retry;