mac80211: remove warning from ieee80211_beacon_loss

Currently, mac80211 assumes that connection monitor offload
for BSS station implies that the device:
- sends periodic keep alive packets to associated AP
- monitors missed beacons
- actively probes the AP in case of missed beacons

In case of poor connection conditions it expects the function
ieee80211_connection_loss() to be called by driver. However,
some devices implement connection monitor offload excluding
active AP probing.

To allow them to call ieee80211_beacon_loss() cleanly, remove
the warning there and thus allow them to use mac80211 for the
AP probing even if connection monitor offload is supported.
Signed-off-by: Alexander Bondar <alexander.bondar@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -2215,7 +2215,6 @@ void ieee80211_beacon_loss(struct ieee80211_vif *vif)
 
 	trace_api_beacon_loss(sdata);
 
-	WARN_ON(hw->flags & IEEE80211_HW_CONNECTION_MONITOR);
 	sdata->u.mgd.connection_loss = false;
 	ieee80211_queue_work(hw, &sdata->u.mgd.beacon_connection_loss_work);
 }