[master] cbc900a Quench another GCC whine

[Poul-Henning Kamp]

commit cbc900aef3274be57facd9c9bb4e240a59d9a2f0
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Tue Aug 30 12:04:18 2016 +0000

    Quench another GCC whine

diff --git a/bin/varnishd/http2/cache_http2_proto.c b/bin/varnishd/http2/cache_http2_proto.c
index e7884b0..e013b6d 100644
--- a/bin/varnishd/http2/cache_http2_proto.c
+++ b/bin/varnishd/http2/cache_http2_proto.c
@@ -303,6 +303,7 @@ h2_rx_goaway(struct worker *wrk, struct h2_sess *h2, struct h2_req *r2)
 	(void)r2;
 	h2->go_away_last_stream = vbe32dec(h2->rxf_data);
 	error = vbe32dec(h2->rxf_data + 4);
+	/*XXX*/(void)error;
 	h2->go_away = 1;
 }