share_pool: Waiting for the migration to complete

ascend inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4EUVI


CVE: NA

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During the u2k, the page is being migrated. Wait
until the migration is complete.

Signed-off-by: Zhou Guanghui <zhouguanghui1@huawei.com>
Reviewed-by: Tang Yizhou <tangyizhou@huawei.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>