mac80211: fix basic rate bitmap calculation

"mac80211: fix basic rates setting from association response"
introduced a copy/paste error.

Unfortunately, this not just leads to wrong data being passed
to the driver but is remotely exploitable for some hardware or
driver combinations.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: stable@kernel.org [2.6.29]
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/mlme.c

@@ -1366,7 +1366,7 @@ static void ieee80211_rx_mgmt_assoc_resp(struct ieee80211_sub_if_data *sdata,
 
 	for (i = 0; i < elems.ext_supp_rates_len; i++) {
 		int rate = (elems.ext_supp_rates[i] & 0x7f) * 5;
-		bool is_basic = !!(elems.supp_rates[i] & 0x80);
+		bool is_basic = !!(elems.ext_supp_rates[i] & 0x80);
 
 		if (rate > 110)
 			have_higher_than_11mbit = true;