mac80211: remove iwlwifi specific workaround that broke sta NDP tx

commit e41eb3e408de27982a5f8f50b2dd8002bed96908 upstream.

Sending nulldata packets is important for sw AP link probing and detecting
4-address mode links. The checks that dropped these packets were apparently
added to work around an iwlwifi firmware bug with multi-TID aggregation.

Fixes: 41cbb0f5a2 ("mac80211: add support for HE")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20210619101517.90806-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -1085,6 +1085,9 @@ static int iwl_mvm_tx_mpdu(struct iwl_mvm *mvm, struct sk_buff *skb,
 	if (WARN_ON_ONCE(mvmsta->sta_id == IWL_MVM_INVALID_STA))
 		return -1;
 
+	if (unlikely(ieee80211_is_any_nullfunc(fc)) && sta->he_cap.has_he)
+		return -1;
+
 	if (unlikely(ieee80211_is_probe_resp(fc)))
 		iwl_mvm_probe_resp_set_noa(mvm, skb);