iwlwifi: introduce beacon context

Only one context can be beaconing at a time,
but we need to track which one. Introduce a
new variable priv->beacon_ctx to do that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index c048c1d..e81c438 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -343,7 +343,8 @@
 		return -ENOMEM;
 	}
 
-	rate = iwl_rate_get_lowest_plcp(priv);
+	rate = iwl_rate_get_lowest_plcp(priv,
+				&priv->contexts[IWL_RXON_CTX_BSS]);
 
 	frame_size = iwl3945_hw_get_beacon_cmd(priv, frame, rate);