ath9k/ath9k_htc: remove redundand checks for dual-stream tx support

mac80211 already masks the HT sta capabilities based on hardware support
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/htc_drv_main.c

@@ -362,11 +362,8 @@ static void ath9k_htc_setup_rate(struct ath9k_htc_priv *priv,
 		trate->rates.ht_rates.rs_nrates = j;
 
 		caps = WLAN_RC_HT_FLAG;
-		if (priv->ah->caps.tx_chainmask != 1 &&
-		    ath9k_hw_getcapability(priv->ah, ATH9K_CAP_DS, 0, NULL)) {
 		if (sta->ht_cap.mcs.rx_mask[1])
 			caps |= WLAN_RC_DS_FLAG;
-		}
 		if (sta->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40)
 			caps |= WLAN_RC_40_FLAG;
 		if (conf_is_ht40(&priv->hw->conf) &&

drivers/net/wireless/ath/ath9k/rc.c

@@ -1203,11 +1203,8 @@ static u8 ath_rc_build_ht_caps(struct ath_softc *sc, struct ieee80211_sta *sta,
 
 	if (sta->ht_cap.ht_supported) {
 		caps = WLAN_RC_HT_FLAG;
-		if (sc->sc_ah->caps.tx_chainmask != 1 &&
-		    ath9k_hw_getcapability(sc->sc_ah, ATH9K_CAP_DS, 0, NULL)) {
 		if (sta->ht_cap.mcs.rx_mask[1])
 			caps |= WLAN_RC_DS_FLAG;
-		}
 		if (is_cw40)
 			caps |= WLAN_RC_40_FLAG;
 		if (is_sgi)