iwlwifi: put use_rts_for_aggregation into hw_params

The hardware config ht_params shouldn't be modified,
so copy the use_rts_for_aggregation parameter into
hw_params and use/modify it there.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-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-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index 116c785..0a898c5 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -2431,7 +2431,7 @@
 	if (cfg(priv)->ht_params)
 		pos += scnprintf(buf + pos, bufsz - pos,
 			 "use %s for aggregation\n",
-			 (cfg(priv)->ht_params->use_rts_for_aggregation) ?
+			 (hw_params(priv).use_rts_for_aggregation) ?
 				"rts/cts" : "cts-to-self");
 	else
 		pos += scnprintf(buf + pos, bufsz - pos, "N/A");
@@ -2458,9 +2458,9 @@
 	if (sscanf(buf, "%d", &rts) != 1)
 		return -EINVAL;
 	if (rts)
-		cfg(priv)->ht_params->use_rts_for_aggregation = true;
+		hw_params(priv).use_rts_for_aggregation = true;
 	else
-		cfg(priv)->ht_params->use_rts_for_aggregation = false;
+		hw_params(priv).use_rts_for_aggregation = false;
 	return count;
 }