hinic: Use ARRAY_SIZE for nic_vf_cmd_msg_handler

fix coccinelle warning, use ARRAY_SIZE

drivers/net/ethernet/huawei/hinic/hinic_sriov.c:713:43-44: WARNING: Use ARRAY_SIZE

v1-->v2:
   remove cmd_number

v2-->v3:
   preserve the reverse christmas tree ordering of local variables

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>