[MAC80211]: Remove overly sticky averaging filters for rssi, signal, noise

The current version of wireless statistics contains a bug in the averaging
that makes the numbers be too sticky and not react to small changes. This
patch removes all averaging.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac80211/rx.c

@@ -485,12 +485,9 @@ ieee80211_rx_h_sta_process(struct ieee80211_txrx_data *rx)
 
 	sta->rx_fragments++;
 	sta->rx_bytes += rx->skb->len;
-	sta->last_rssi = (sta->last_rssi * 15 +
-			  rx->u.rx.status->ssi) / 16;
-	sta->last_signal = (sta->last_signal * 15 +
-			    rx->u.rx.status->signal) / 16;
-	sta->last_noise = (sta->last_noise * 15 +
-			   rx->u.rx.status->noise) / 16;
+	sta->last_rssi = rx->u.rx.status->ssi;
+	sta->last_signal = rx->u.rx.status->signal;
+	sta->last_noise = rx->u.rx.status->noise;
 
 	if (!(rx->fc & IEEE80211_FCTL_MOREFRAGS)) {
 		/* Change STA power saving mode only in the end of a frame