iwlwifi: use singlethread workqueue

Use one workqueue instead of one per CPU.
Signed-off-by: NReinette Chatre <reinette.chatre@intel.com>
cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-agn.c

@@ -3370,7 +3370,7 @@ static DEVICE_ATTR(statistics, S_IRUGO, show_statistics, NULL);
 
 static void iwl_setup_deferred_work(struct iwl_priv *priv)
 {
-	priv->workqueue = create_workqueue(DRV_NAME);
+	priv->workqueue = create_singlethread_workqueue(DRV_NAME);
 
 	init_waitqueue_head(&priv->wait_command_queue);
 

drivers/net/wireless/iwlwifi/iwl3945-base.c

@@ -5201,7 +5201,7 @@ static DEVICE_ATTR(dump_events, S_IWUSR, NULL, dump_event_log);
 
 static void iwl3945_setup_deferred_work(struct iwl_priv *priv)
 {
-	priv->workqueue = create_workqueue(DRV_NAME);
+	priv->workqueue = create_singlethread_workqueue(DRV_NAME);
 
 	init_waitqueue_head(&priv->wait_command_queue);