net/ipv6: Put lwtstate when destroying fib6_info

Prior to the introduction of fib6_info lwtstate was managed by the dst
code. With fib6_info releasing lwtstate needs to be done when the struct
is freed.

Fixes: 93531c67 ("net/ipv6: separate handling of FIB entries from dst based routes")
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ip6_fib.c

@@ -198,6 +198,8 @@ void fib6_info_destroy_rcu(struct rcu_head *head)
 		}
 	}
 
+	lwtstate_put(f6i->fib6_nh.nh_lwtstate);
+
 	if (f6i->fib6_nh.nh_dev)
 		dev_put(f6i->fib6_nh.nh_dev);