mm: reliable: Use EINVAL in reliable_check

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S
CVE: NA

--------------------------------

LTP's proc01 test was failing be because this ret code (1):

	proc01      1  TFAIL  :  proc01.c:400: read failed: /proc/self/task/1406366/reliable: errno=EPERM(1): Operation not permitted

To slove this problem, replace EPERM with EINVAL in reliable_check().
Signed-off-by: NMa Wupeng <mawupeng1@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/proc/base.c

@@ -1264,14 +1264,14 @@ static const struct file_operations proc_oom_score_adj_operations = {
 static inline int reliable_check(struct task_struct *task, struct pid *pid)
 {
 	if (!mem_reliable_is_enabled())
-		return -EPERM;
+		return -EINVAL;
 
 	if (is_global_init(task))
-		return -EPERM;
+		return -EINVAL;
 
 	if (!task->mm || (task->flags & PF_KTHREAD) ||
 	    (task->flags & PF_EXITING))
-		return -EPERM;
+		return -EINVAL;
 
 	return 0;
 }