ethernet: 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 <elfring@users.sourceforge.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/intel/e1000e/ethtool.c

@@ -1126,8 +1126,7 @@ static void e1000_free_desc_rings(struct e1000_adapter *adapter)
 						 buffer_info->dma,
 						 buffer_info->length,
 						 DMA_TO_DEVICE);
-			if (buffer_info->skb)
-				dev_kfree_skb(buffer_info->skb);
+			dev_kfree_skb(buffer_info->skb);
 		}
 	}
 
@@ -1139,8 +1138,7 @@ static void e1000_free_desc_rings(struct e1000_adapter *adapter)
 				dma_unmap_single(&pdev->dev,
 						 buffer_info->dma,
 						 2048, DMA_FROM_DEVICE);
-			if (buffer_info->skb)
-				dev_kfree_skb(buffer_info->skb);
+			dev_kfree_skb(buffer_info->skb);
 		}
 	}