mac80211: don't allow 40MHz tx rates in case of 20MHz chandef

When 20MHz chandef is used, 40MHz rates shouldn't be
used (by the rate-control algorithm), even if the sta
ht capabilities indicate support for it.
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Singed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

net/mac80211/vht.c

@@ -287,6 +287,8 @@ enum ieee80211_sta_rx_bandwidth ieee80211_sta_cur_vht_bw(struct sta_info *sta)
 		/* fall through */
 	case NL80211_CHAN_WIDTH_20_NOHT:
 	case NL80211_CHAN_WIDTH_20:
+		bw = IEEE80211_STA_RX_BW_20;
+		break;
 	case NL80211_CHAN_WIDTH_40:
 		bw = sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;