mac80211: quit addba_resp_timer if Tx BA session is torn down

Make addba_resp_timer aware the HT_AGG_STATE_REQ_STOP_BA_MSK mask
so that when ___ieee80211_stop_tx_ba_session() is issued the timer
will quit. Otherwise when suspend happens before the timer expired,
the timer handler will be called immediately after resume and
messes up driver status.

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>