net: hns3: Change fw error code NOT_EXEC to NOT_SUPPORTED

According to firmware error code definition, the error code of 2
means NOT_SUPPORTED, this patch changes it to NOT_SUPPORTED.

Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>