geneve, vxlan: Don't check skb_dst() twice

Commit f15ca723 ("net: don't call update_pmtu unconditionally") avoids
that we try updating PMTU for a non-existent destination, but didn't clean
up cases where the check was already explicit. Drop those redundant checks.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/geneve.c

@@ -830,12 +830,8 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	if (IS_ERR(rt))
 		return PTR_ERR(rt);
 
-	if (skb_dst(skb)) {
-		int mtu = dst_mtu(&rt->dst) - GENEVE_IPV4_HLEN -
-			  info->options_len;
-
-		skb_dst_update_pmtu(skb, mtu);
-	}
+	skb_dst_update_pmtu(skb, dst_mtu(&rt->dst) -
+				 GENEVE_IPV4_HLEN - info->options_len);
 
 	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
 	if (geneve->collect_md) {
@@ -876,11 +872,8 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
 	if (IS_ERR(dst))
 		return PTR_ERR(dst);
 
-	if (skb_dst(skb)) {
-		int mtu = dst_mtu(dst) - GENEVE_IPV6_HLEN - info->options_len;
-
-		skb_dst_update_pmtu(skb, mtu);
-	}
+	skb_dst_update_pmtu(skb, dst_mtu(dst) -
+				 GENEVE_IPV6_HLEN - info->options_len);
 
 	sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
 	if (geneve->collect_md) {

drivers/net/vxlan.c

@@ -2194,11 +2194,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 		}
 
 		ndst = &rt->dst;
-		if (skb_dst(skb)) {
-			int mtu = dst_mtu(ndst) - VXLAN_HEADROOM;
-
-			skb_dst_update_pmtu(skb, mtu);
-		}
+		skb_dst_update_pmtu(skb, dst_mtu(ndst) - VXLAN_HEADROOM);
 
 		tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
 		ttl = ttl ? : ip4_dst_hoplimit(&rt->dst);
@@ -2235,11 +2231,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 				goto out_unlock;
 		}
 
-		if (skb_dst(skb)) {
-			int mtu = dst_mtu(ndst) - VXLAN6_HEADROOM;
-
-			skb_dst_update_pmtu(skb, mtu);
-		}
+		skb_dst_update_pmtu(skb, dst_mtu(ndst) - VXLAN6_HEADROOM);
 
 		tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
 		ttl = ttl ? : ip6_dst_hoplimit(ndst);