ethernet/intel: Use eth_skb_pad and skb_put_padto helpers

Update the Intel Ethernet drivers to use eth_skb_pad() and skb_put_padto
instead of doing their own implementations of the function.

Also this cleans up two other spots where skb_pad was called but the length
and tail pointers were being manipulated directly instead of just having
the padding length added via __skb_put.

Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index 3195d82..04b4414 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2399,12 +2399,8 @@
 	/* hardware can't handle really short frames, hardware padding works
 	 * beyond this point
 	 */
-	if (unlikely(skb->len < I40E_MIN_TX_LEN)) {
-		if (skb_pad(skb, I40E_MIN_TX_LEN - skb->len))
-			return NETDEV_TX_OK;
-		skb->len = I40E_MIN_TX_LEN;
-		skb_set_tail_pointer(skb, I40E_MIN_TX_LEN);
-	}
+	if (skb_put_padto(skb, I40E_MIN_TX_LEN))
+		return NETDEV_TX_OK;
 
 	return i40e_xmit_frame_ring(skb, tx_ring);
 }