kasan: add kasan support for memcpy_mcs()

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


CVE: NA

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

Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>