mac80211: fix logic error in ibss channel type check

The broken check leads to rate control attempting to use HT40 while
the driver is configured for HT20. This leads to interesting hardware
issues.

HT40 can only be used if the channel type is either HT40- or HT40+
and if the channel type of the cell matches the local type.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Cc: stable@vger.kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/ibss.c

@@ -457,8 +457,8 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 			 * fall back to HT20 if we don't use or use
 			 * the other extension channel
 			 */
-			if ((channel_type == NL80211_CHAN_HT40MINUS ||
-			     channel_type == NL80211_CHAN_HT40PLUS) &&
+			if (!(channel_type == NL80211_CHAN_HT40MINUS ||
+			      channel_type == NL80211_CHAN_HT40PLUS) ||
 			    channel_type != sdata->u.ibss.channel_type)
 				sta_ht_cap_new.cap &=
 					~IEEE80211_HT_CAP_SUP_WIDTH_20_40;