openvswitch: load NAT helper

Load the respective NAT helper module if the flow uses it.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 0aeb34c..35ae64c 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1312,6 +1312,10 @@
 
 	rcu_assign_pointer(help->helper, helper);
 	info->helper = helper;
+
+	if (info->nat)
+		request_module("ip_nat_%s", name);
+
 	return 0;
 }