lwtunnel: fix memory leak

The built lwtunnel_state struct has to be freed after comparison.

Fixes: 571e722676fe3 ("ipv4: support for fib route lwtunnel encap attributes")
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index c802585..d525307 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -539,7 +539,7 @@
 {
 	struct lwtunnel_state *lwtstate;
 	struct net_device *dev = NULL;
-	int ret;
+	int ret, result = 0;
 
 	if (encap_type == LWTUNNEL_ENCAP_NONE)
 		return 0;
@@ -548,10 +548,12 @@
 		dev = __dev_get_by_index(net, oif);
 	ret = lwtunnel_build_state(dev, encap_type,
 				   encap, &lwtstate);
-	if (!ret)
-		return lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate);
+	if (!ret) {
+		result = lwtunnel_cmp_encap(lwtstate, nh->nh_lwtstate);
+		lwtstate_free(lwtstate);
+	}
 
-	return 0;
+	return result;
 }
 
 int fib_nh_match(struct fib_config *cfg, struct fib_info *fi)