iwlwifi: mvm: free RX reorder buffer on restart

Restart flow zeroes the rx_ba_sessions counter. Mac80211 asks
driver to tear down of the session only afterwards, and as a
result driver didn't free the data. Fix it.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Fixes: 10b2b201 ("iwlwifi: mvm: add infrastructure for tracking BA session in driver")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/sta.c

@@ -1828,11 +1828,12 @@ int iwl_mvm_sta_rx_agg(struct iwl_mvm *mvm, struct ieee80211_sta *sta,
 			     mvm_sta->sta_id, tid, baid);
 		WARN_ON(rcu_access_pointer(mvm->baid_map[baid]));
 		rcu_assign_pointer(mvm->baid_map[baid], baid_data);
-	} else if (mvm->rx_ba_sessions > 0) {
+	} else  {
 		u8 baid = mvm_sta->tid_to_baid[tid];
 
-		/* check that restart flow didn't zero the counter */
-		mvm->rx_ba_sessions--;
+		if (mvm->rx_ba_sessions > 0)
+			/* check that restart flow didn't zero the counter */
+			mvm->rx_ba_sessions--;
 		if (!iwl_mvm_has_new_rx_api(mvm))
 			return 0;