share_pool: Rename function is_k2task to sp_check_k2task

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


CVE: NA

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

Add a new field to_task in struct sp_k2u_context, then is_k2task
doesn't need magic number return values.

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