ipvs: lvs sctp protocol handler is incorrectly invoked ip_vs_app_pkt_out

lvs sctp protocol handler is incorrectly invoked ip_vs_app_pkt_out
Since there's no sctp helpers at present, it does the same thing as
ip_vs_app_pkt_in.

Signed-off-by: Xiaoyu Du <tingsrain@gmail.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>

net/netfilter/ipvs/ip_vs_proto_sctp.c

@@ -173,7 +173,7 @@ sctp_dnat_handler(struct sk_buff *skb,
 			return 0;
 
 		/* Call application helper if needed */
-		if (!ip_vs_app_pkt_out(cp, skb))
+		if (!ip_vs_app_pkt_in(cp, skb))
 			return 0;
 	}