mac80211: fix RX path

My previous patch ("mac80211: remove mixed-cell and userspace MLME code")
was too obvious to me, so obvious that a stupid bug crept in. The IBSS
RX function must be invoked for IBSS, of course, not anything != IBSS.
Reported-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Tested-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

net/mac80211/rx.c

@@ -1884,7 +1884,7 @@ ieee80211_rx_h_mgmt(struct ieee80211_rx_data *rx)
 	if (ieee80211_vif_is_mesh(&sdata->vif))
 		return ieee80211_mesh_rx_mgmt(sdata, rx->skb, rx->status);
 
-	if (sdata->vif.type != NL80211_IFTYPE_ADHOC)
+	if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
 		return ieee80211_ibss_rx_mgmt(sdata, rx->skb, rx->status);
 
 	if (sdata->vif.type == NL80211_IFTYPE_STATION)