[PATCH net-next] net: core: fix compile error inside flow_dissector due to new dsa callback

[John Crispin]

The following error was introduced by
commit 43e665287f93 ("net-next: dsa: fix flow dissection")
due to a missing #if guard

net/core/flow_dissector.c: In function '__skb_flow_dissect':
net/core/flow_dissector.c:448:18: error: 'struct net_device' has no member 
named 'dsa_ptr'
ops = skb->dev->dsa_ptr->tag_ops;
                ^
make[3]: *** [net/core/flow_dissector.o] Error 1

Signed-off-by: John Crispin <j...@phrozen.org>
---
 net/core/flow_dissector.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index 5b5be9577257..79b9c06c83ad 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -441,6 +441,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
                         skb->vlan_proto : skb->protocol;
                nhoff = skb_network_offset(skb);
                hlen = skb_headlen(skb);
+#if IS_ENABLED(CONFIG_NET_DSA)
                if (unlikely(netdev_uses_dsa(skb->dev))) {
                        const struct dsa_device_ops *ops;
                        int offset;
@@ -452,6 +453,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
                                nhoff += offset;
                        }
                }
+#endif
        }
 
        /* It is ensured by skb_flow_dissector_init() that control key will
-- 
2.11.0