ath9k: make use of conf_is_ht*() in the rest of the driver

Use shiny new conf_is_ht*() helpers, we can later remove ht.enabled if
desired.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index 7d9a263..7566044 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -2132,9 +2132,8 @@
 			(curchan->band == IEEE80211_BAND_2GHZ) ?
 			CHANNEL_G : CHANNEL_A;
 
-		if (conf->ht.enabled) {
-			if (conf->ht.channel_type == NL80211_CHAN_HT40PLUS ||
-			    conf->ht.channel_type == NL80211_CHAN_HT40MINUS)
+		if (conf_is_ht(conf)) {
+			if (conf_is_ht40(conf))
 				sc->tx_chan_width = ATH9K_HT_MACMODE_2040;
 
 			sc->sc_ah->ah_channels[pos].chanmode =
@@ -2142,7 +2141,7 @@
 						    conf->ht.channel_type);
 		}
 
-		ath_update_chainmask(sc, conf->ht.enabled);
+		ath_update_chainmask(sc, conf_is_ht(conf));
 
 		if (ath_set_channel(sc, &sc->sc_ah->ah_channels[pos]) < 0) {
 			DPRINTF(sc, ATH_DBG_FATAL, "Unable to set channel\n");