proc: Fix reliable display err in /proc/pid/status

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S


CVE: NA

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Reliable memory used shown in /proc/pid/status is incorrect because this
var is about page count. So (PAGE_SHIFT - 10) is multiplied to get correct
size in kB.

Fixes: 094eaabb ("proc: Count reliable memory usage of reliable tasks")
Signed-off-by: Peng Wu <wupeng58@huawei.com>
Reviewed-by: Kefeng <Wang&lt;wangkefeng.wang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>