skbuff: add check for non-linear to warn_if_lro and needs_linearize

We can avoid an unecessary cache miss by checking if the skb is non-linear
before accessing gso_size/gso_type in skb_warn_if_lro, the same can also be
done to avoid a cache miss on nr_frags if data_len is 0.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index ec01a59..3abb3a6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2103,9 +2103,10 @@
 static inline int skb_needs_linearize(struct sk_buff *skb,
 				      struct net_device *dev)
 {
-	return (skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
-	       (skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
-					      illegal_highdma(dev, skb)));
+	return skb_is_nonlinear(skb) &&
+	       ((skb_has_frags(skb) && !(dev->features & NETIF_F_FRAGLIST)) ||
+	        (skb_shinfo(skb)->nr_frags && (!(dev->features & NETIF_F_SG) ||
+					      illegal_highdma(dev, skb))));
 }
 
 /**