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-6000.c b/drivers/net/wireless/iwlwifi/iwl-6000.c
index f4bec32..af505bc 100644
--- a/drivers/net/wireless/iwlwifi/iwl-6000.c
+++ b/drivers/net/wireless/iwlwifi/iwl-6000.c
@@ -596,12 +596,7 @@
 	.need_dc_calib = true,					\
 	.need_temp_offset_calib = true,				\
 	.led_mode = IWL_LED_RF_STATE,				\
-	.adv_pm = true,						\
-	/*							\
-	 *Due to bluetooth, we transmit 2.4 GHz probes		\
-	 * only on antenna A					\
-	 */							\
-	.scan_tx_antennas[IEEE80211_BAND_2GHZ] = ANT_A
+	.adv_pm = true						\
 
 struct iwl_cfg iwl6030_2agn_cfg = {
 	.name = "Intel(R) Centrino(R) Advanced-N 6230 AGN",