net: usb: Delete unnecessary checks before the macro call “dev_kfree_skb”

The dev_kfree_skb() function performs also input parameter validation.
Thus the test around the shown calls is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/usb/lg-vl600.c

···
 {
 	struct vl600_state *s = dev->driver_priv;
 
-	if (s->current_rx_buf)
-		dev_kfree_skb(s->current_rx_buf);
-
+	dev_kfree_skb(s->current_rx_buf);
 	kfree(s);
 
 	return usbnet_cdc_unbind(dev, intf);

drivers/net/usb/rtl8150.c

···
 	int i;
 
 	for (i = 0; i < RX_SKB_POOL_SIZE; i++)
-		if (dev->rx_skb_pool[i])
-			dev_kfree_skb(dev->rx_skb_pool[i]);
+		dev_kfree_skb(dev->rx_skb_pool[i]);
 }
 
 static void rx_fixup(unsigned long data)
···
 		unlink_all_urbs(dev);
 		free_all_urbs(dev);
 		free_skb_pool(dev);
-		if (dev->rx_skb)
-			dev_kfree_skb(dev->rx_skb);
+		dev_kfree_skb(dev->rx_skb);
 		kfree(dev->intr_buff);
 		free_netdev(dev->netdev);
 	}