[master] 9cc77a4 Add an assert for Coverity

[Poul-Henning Kamp]

commit 9cc77a45a85b611f7e45058aa0f0d25fb43917fb
Author: Poul-Henning Kamp <phk at FreeBSD.org>
Date:   Mon Oct 20 07:33:38 2014 +0000

    Add an assert for Coverity

diff --git a/bin/varnishd/cache/cache_backend.c b/bin/varnishd/cache/cache_backend.c
index 6d99562..c796ea7 100644
--- a/bin/varnishd/cache/cache_backend.c
+++ b/bin/varnishd/cache/cache_backend.c
@@ -361,6 +361,7 @@ vbe_dir_getfd(const struct director *d, struct busyobj *bo)
 
 	if (bo->htc == NULL)
 		bo->htc = WS_Alloc(bo->ws, sizeof *bo->htc);
+	AN(bo->htc);
 	memset(bo->htc, 0, sizeof *bo->htc);
 	bo->htc->magic = HTTP_CONN_MAGIC;
 	bo->htc->vbc = vc;