[][kernel][common][hnat][Refine HNAT prefilled flow for the WiFi Tx]

[Description]
Refactor HNAT prefilled flow for the WiFi Tx.

If without this patch, the HNAT BIND info might be dameged by
skb_to_hnat_info() in the WiFi Tx case.

[Release-log]
N/A


Change-Id: I00602dcdeabb6e04a053b56c9a4bd2a72ebb853e
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7658230
3 files changed