iwlagn: Remove un-necessary indirect call

After driver split, no need to make indirect call to txfifo flush function

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
index a8c1e24..3d9e1e8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
@@ -1546,7 +1546,7 @@
 {
 	mutex_lock(&priv->mutex);
 	ieee80211_stop_queues(priv->hw);
-	if (priv->cfg->ops->lib->txfifo_flush(priv, IWL_DROP_ALL)) {
+	if (iwlagn_txfifo_flush(priv, IWL_DROP_ALL)) {
 		IWL_ERR(priv, "flush request fail\n");
 		goto done;
 	}