As far as I can tell, there are possible lockups because both the RX
session_timer and TX addba_resp_timer are del_timer_sync'ed under
the sta spinlock which both timer functions take. Additionally, the
TX agg code seems to leak memory when TX aggregation is not disabled
before the sta_info is freed.

Fix this by making the free code a little smarter in the RX agg case,
and actually make the sta_info_destroy code free the TX agg info in
the TX agg case. We won't notify the peer, but it'll notice something
is wrong anyway, and normally this only happens after we've told it
in some other way we will no longer talk to it.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We can only support aggregation on AP/STA right now. HT isn't defined
for IBSS, WDS or MESH. In the WDS/MESH cases it's not clear what to
put into the IBSS field, and we don't handle that in the code at all.
Also fix the code to handle VLAN correctly.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Create two new files, agg-tx.c and agg-rx.c to make it clearer
which code is common (ht.c) and which is specific (agg-*.c).
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>