fix job::wait-for-next-job to properly return the next available job

src/jobs.lisp

@@ -11,6 +11,7 @@
         :thread
         :containers)
   (:export :job
+           :job-result
            :push-job
            :wait-for-job
            :cancel-job))
@@ -149,7 +150,8 @@ Return t if job has been successfully canceled, nil if it currently running."
       (condition-wait waitqueue lock)
       (when (peek job-list)
         (setf job (dequeue job-list))
-        (setf (job-running job) t)))))
+        (setf (job-running job) t))
+      job)))
 
 (defun thread-loop (thread)
   "Run the thread loop.