kasan: add kasan support for memcpy_mcs()

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I6AQE8


CVE: NA

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

The function memcpy_mcs() is designed to copy in memory and should be
supported by kasan.

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
(cherry picked from commit 525213f1)