update CODEOWNERS.

删除csv文件owner, 防止出现必须两人同时审查才允许合入的问题
Signed-off-by: Nmamingshuai <mamingshuai1@huawei.com>

CODEOWNERS

-README.md @landwind
-matrix_product.csv @leather0906
\ No newline at end of file
+README.md @landwind
\ No newline at end of file