net: ravb: Simplify UDP TX checksum offload

The GbEth IP will pass through a zero UDP checksum without asserting any
error flags so we do not need to resort to software checksum calculation
in this case.

Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>

drivers/net/ethernet/renesas/ravb_main.c

@@ -2075,20 +2075,11 @@ static bool ravb_can_tx_csum_gbeth(struct sk_buff *skb)
 
 	switch (ip->protocol) {
 	case IPPROTO_TCP:
-		break;
 	case IPPROTO_UDP:
-		/* If the checksum value in the UDP header field is 0, TOE does
-		 * not calculate checksum for UDP part of this frame as it is
-		 * optional function as per standards.
-		 */
-		if (udp_hdr(skb)->check == 0)
-			return false;
-		break;
+		return true;
 	default:
 		return false;
 	}
-
-	return true;
 }
 
 /* Packet transmit function for Ethernet AVB */