ipv6: xfrm6_tunnel.c: Use built-in RCU list checking

hlist_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/ipv6/xfrm6_tunnel.c

@@ -78,7 +78,7 @@ static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(struct net *net, const
 
 	hlist_for_each_entry_rcu(x6spi,
 			     &xfrm6_tn->spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
-			     list_byaddr) {
+			     list_byaddr, lockdep_is_held(&xfrm6_tunnel_spi_lock)) {
 		if (xfrm6_addr_equal(&x6spi->addr, saddr))
 			return x6spi;
 	}