Constify arg to HSH_Ref()

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@4825 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/cache_hash.c

@@ -595,7 +595,7 @@ HSH_Unbusy(const struct sess *sp)
 }
 
 void
-HSH_Ref(struct object *o)
+HSH_Ref(const struct object *o)
 {
 	struct objhead *oh;
 

bin/varnishd/hash_slinger.h

@@ -56,7 +56,7 @@ void HSH_Cleanup(struct worker *w);
 void HSH_Freestore(struct object *o);
 struct objcore *HSH_Lookup(struct sess *sp, struct objhead **poh);
 void HSH_Unbusy(const struct sess *sp);
-void HSH_Ref(struct object *o);
+void HSH_Ref(const struct object *o);
 void HSH_Drop(struct sess *sp);
 double HSH_Grace(double g);
 void HSH_Init(void);