iwlwifi: scan correct setting of valid rx_chains

This patch sets rx_chain bitmap correctly according hw configuration.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
index bf855c3..debdbd9 100644
--- a/drivers/net/wireless/iwlwifi/iwl-scan.c
+++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
@@ -703,7 +703,7 @@
 	u16 cmd_len;
 	enum ieee80211_band band;
 	u8 n_probes = 2;
-	u8 rx_chain = 0x7; /* bitmap: ABC chains */
+	u8 rx_chain = priv->hw_params.valid_rx_ant;
 
 	conf = ieee80211_get_hw_conf(priv->hw);