[master] 08430eb16 Add a trivial clarifying assertion

[Nils Goroll]

commit 08430eb1666640580ac17c03764809c4bd320b1b
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Sat Sep 24 17:26:29 2022 +0200

    Add a trivial clarifying assertion

diff --git a/bin/varnishd/cache/cache_hash.c b/bin/varnishd/cache/cache_hash.c
index a8bd61f5b..337727c99 100644
--- a/bin/varnishd/cache/cache_hash.c
+++ b/bin/varnishd/cache/cache_hash.c
@@ -861,6 +861,8 @@ HSH_Unbusy(struct worker *wrk, struct objcore *oc)
 
 	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
 	CHECK_OBJ_NOTNULL(oc, OBJCORE_MAGIC);
+	CHECK_OBJ_NOTNULL(oc->boc, BOC_MAGIC);
+
 	oh = oc->objhead;
 	CHECK_OBJ(oh, OBJHEAD_MAGIC);
 	INIT_OBJ(&rush, RUSH_MAGIC);