net: ethernet: mtk_wed: do not assume offload callbacks are always set

Check if wlan.offload_enable and wlan.offload_disable callbacks are set
in mtk_wed_flow_add/mtk_wed_flow_remove since mt7996 will not rely
on them.

Signed-off-by: Lorenzo Bianconi <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/mediatek/mtk_wed.c

···
 int mtk_wed_flow_add(int index)
 {
 	struct mtk_wed_hw *hw = hw_list[index];
-	int ret;
+	int ret = 0;
 
-	if (!hw || !hw->wed_dev)
-		return -ENODEV;
+	mutex_lock(&hw_lock);
+
+	if (!hw || !hw->wed_dev) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (!hw->wed_dev->wlan.offload_enable)
+		goto out;
 
 	if (hw->num_flows) {
 		hw->num_flows++;
-		return 0;
-	}
-
-	mutex_lock(&hw_lock);
-	if (!hw->wed_dev) {
-		ret = -ENODEV;
 		goto out;
 	}
 
···
 {
 	struct mtk_wed_hw *hw = hw_list[index];
 
-	if (!hw)
-		return;
+	mutex_lock(&hw_lock);
+
+	if (!hw || !hw->wed_dev)
+		goto out;
+
+	if (!hw->wed_dev->wlan.offload_disable)
+		goto out;
 
 	if (--hw->num_flows)
-		return;
-
-	mutex_lock(&hw_lock);
-	if (!hw->wed_dev)
 		goto out;
 
 	hw->wed_dev->wlan.offload_disable(hw->wed_dev);