mac80211: fix regression in SSN handling of addba tx

mac80211: fix regression in SSN handling of addba tx

Some drivers that do their own sequence number allocation (e.g. ath9k) rely
on being able to modify params->ssn on starting tx ampdu sessions.
This was broken by a change that modified it to use sta->tid_seq[tid] instead.

Cc: stable@vger.kernel.org
Fixes: 31d8bb4e07f8 ("mac80211: agg-tx: refactor sending addba")
Reported-by: Eneas U de Queiroz <cotequeiroz@gmail.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20211124094024.43222-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>