LinuxKPI: 802.11: reset hdr after crypto in lkpi_80211_txq_tx_one()

When lkpi_80211_txq_tx_one() calls into the crypto offloading parts to
possibly make space in the headroom, the beginning of our frame moves.
We have to reset hdr after that call as otherwise later classifications
based on the hdr->frame_control will fail or cause wrong classificaiton
of packets.
This makes sure frames will either be directly sent using (*mo_tx)()
or use the correct tid for the correct queue. This helps to get
rtwx8 packets flowing after BA was negotiated.

Sponsored by: The FreeBSD Foundation
MFC after: 3 days
Fixes: 11db70b6057e4