Have spawn-revokeable use multi-value-return

goblins/actor-lib/revokeable.rkt

@@ -18,12 +18,13 @@
        (keyword-apply $/<- kws kw-args target args))))
   (define ((^revoker bcom))
     ($ revoked? #t))
-  (list (spawn ^forwarder) (spawn ^revoker)))
+  (values (spawn ^forwarder) (spawn ^revoker)))
 
 (module+ test
   (require rackunit
            racket/match
-           racket/contract)
+           racket/contract
+           "../utils/values-to-list.rkt")
   (define am (make-actormap))
   (define royal-admission
     (actormap-spawn!
@@ -33,7 +34,7 @@
   (match-define (list royal-forwarder royal-revoker)
     (actormap-run! am
                    (lambda ()
-                     (spawn-revokeable royal-admission))))
+                     (values->list (spawn-revokeable royal-admission)))))
 
   (check-equal?
    (actormap-peek am royal-forwarder)