net: hns3: fix VF dump register issue

In original codes, the .get_regs_len and .get_regs were missed
assigned. This patch fixes it.

Fixes: 1600c3e5 ("net: hns3: Support "ethtool -d" for HNS3 VF driver")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>