net: hns3: pad the short tunnel frame before sending to hardware

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

----------------------------

The hardware can not handle short tunnel frames below or equal
to 64 bytes, and will cause vlan tag missing problem.

This patch pads packet size to 65 bytes for tunnel frames to
fix this bug.

Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Reviewed-by: Junxin Chen <chenjunxin1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>