net: hns3: fix rss configuration lost problem when setting channel

Currently rss configuration set by user will be lost when setting
channel.

This patch fixes it by not setting rss configuration to default
if user has configured the rss.

Fixes: 09f2af64

 ("net: hns3: add support to modify tqps number")
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>