Make the object length a ssize_t

bin/varnishd/cache.h

@@ -432,7 +432,7 @@ struct object {
 
 	unsigned		cacheable;
 
-	unsigned		len;
+	ssize_t			len;
 
 	double			ttl;
 	double			age;

bin/varnishd/cache_response.c

@@ -297,7 +297,7 @@ res_WriteDirObj(struct sess *sp, char lenbuf[20], size_t low, size_t high)
 	CHECK_OBJ_NOTNULL(sp, SESS_MAGIC);
 
 	if (sp->wrk->res_mode & RES_CHUNKED) {
-		bprintf(lenbuf, "%x\r\n", sp->obj->len);
+		bprintf(lenbuf, "%jx\r\n", (intmax_t)sp->obj->len);
 		(void)WRW_Write(sp->wrk, lenbuf, -1);
 	}