iwlagn: fix scan tx antenna setting on 5Ghz band

Looks that we do not set correctly antennas when scanning
on 5Ghz band and when bluetooth is enabled, because
priv->cfg->scan_tx_antennas[band] is only defined for
IEEE80211_BAND_2GHZ.

To fix we check band before limiting antennas to first one.
This allow to remove hard coded cfg->scan_tx_antennas[band].

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
index 4bc82fc..3dee87e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
@@ -1492,15 +1492,11 @@
 	if (priv->cfg->scan_rx_antennas[band])
 		rx_ant = priv->cfg->scan_rx_antennas[band];
 
-	if (priv->cfg->scan_tx_antennas[band])
-		scan_tx_antennas = priv->cfg->scan_tx_antennas[band];
-
-	if (priv->cfg->bt_params &&
-	    priv->cfg->bt_params->advanced_bt_coexist &&
-	    priv->bt_full_concurrent) {
-		/* operated as 1x1 in full concurrency mode */
-		scan_tx_antennas = first_antenna(
-			priv->cfg->scan_tx_antennas[band]);
+	if (band == IEEE80211_BAND_2GHZ &&
+	    priv->cfg->bt_params &&
+	    priv->cfg->bt_params->advanced_bt_coexist) {
+		/* transmit 2.4 GHz probes only on first antenna */
+		scan_tx_antennas = first_antenna(scan_tx_antennas);
 	}
 
 	priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band],