net: hns3: modify the upper limit judgment condition

In order to prevent the variable anomaly from being larger than desc_num,
the upper limit judgment condition becomes >=.

Signed-off-by: liuzhongzhu <liuzhongzhu@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>