iwlwifi: mvm: free AGG queue when we STA is removed

iwlwifi: mvm: free AGG queue when we STA is removed

When we stop an AGG session, we need to look at the sequence
numbers in in the private area of the ieee80211_sta struct.
This allows us to know is the queue is empty. To get access
to this private area, we use fw_id_to_mac_id that maps
sta_id (index of the STA in fw table) to ieee80211_sta.

When the STA exists in fw, but not in mac80211, we set
an ERR ptr in fw_id_to_mac_id.

But if we first set an ERR ptr to fw_id_to_mac_id, and only
then flush the queues, then we won't be able to access the
sequence numbers in ieee80211_sta from the reclaim flow.
This means that we will never be able to release an AGG
queue when a station is deleted.

So first, flush the queue. That will let the reclaim flow
call iwl_mvm_check_ratid_empty which will disable the AGG
queue as needed, and only then, remove the mapping in
fw_id_to_mac_id.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>