s390/qeth: remove skb_is_nonlinear() check on IQD

qeth doesn't advertise NETIF_F_SG for L3 IQDs. So trust the stack to
not hand us any nonlinear skbs, and remove an always-true condition.

With the fact that data_offset < 0 is no longer possible on IQDs,
apply a small cleanup to subsequent code.
Signed-off-by: NJulian Wiedmann <jwi@linux.vnet.ibm.com>
Acked-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/s390/net/qeth_l3_main.c

@@ -2676,8 +2676,7 @@ static netdev_tx_t qeth_l3_hard_start_xmit(struct sk_buff *skb,
 	use_tso = skb_is_gso(skb) &&
 		  (qeth_get_ip_protocol(skb) == IPPROTO_TCP) && (ipv == 4);
 
-	if ((card->info.type == QETH_CARD_TYPE_IQD) &&
-	    !skb_is_nonlinear(skb)) {
+	if (card->info.type == QETH_CARD_TYPE_IQD) {
 		new_skb = skb;
 		data_offset = ETH_HLEN;
 		hdr = kmem_cache_alloc(qeth_core_header_cache, GFP_ATOMIC);
@@ -2690,12 +2689,7 @@ static netdev_tx_t qeth_l3_hard_start_xmit(struct sk_buff *skb,
 					+ VLAN_HLEN);
 		if (!new_skb)
 			goto tx_drop;
-	}
 
-	if (card->info.type == QETH_CARD_TYPE_IQD) {
-		if (data_offset < 0)
-			skb_pull(new_skb, ETH_HLEN);
-	} else {
 		if (ipv == 4) {
 			skb_pull(new_skb, ETH_HLEN);
 		}