openvswitch: fix sparse warning incorrect type

fix incorrect type in argument 1 (different address spaces)

../net/openvswitch/datapath.c:169:17: warning: incorrect type in argument 1 (different address spaces)
../net/openvswitch/datapath.c:169:17:    expected void const *
../net/openvswitch/datapath.c:169:17:    got struct dp_nlsk_pids [noderef] __rcu *upcall_portids

Found at: https://patchwork.kernel.org/project/netdevbpf/patch/20210630095350.817785-1-mark.d.gray@redhat.com/#24285159Signed-off-by: NMark Gray <mark.d.gray@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/openvswitch/datapath.c

@@ -168,7 +168,7 @@ static void destroy_dp_rcu(struct rcu_head *rcu)
 	free_percpu(dp->stats_percpu);
 	kfree(dp->ports);
 	ovs_meters_exit(dp);
-	kfree(dp->upcall_portids);
+	kfree(rcu_dereference_raw(dp->upcall_portids));
 	kfree(dp);
 }