When the fraglist SKB headlen is larger than zero, current code
still handle the fraglist SKB linear data as frag data, which may
cause TX error.

This patch adds a new DESC_TYPE_FRAGLIST_SKB type to handle the
mapping and unmapping of the fraglist SKB linear data buffer.

Fixes: 8ae10cfb ("net: hns3: support tx-scatter-gather-fraglist feature")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>