Use getticks() to get enough randomness when enqueing tasks without owners.

src/scheduler.c

@@ -1381,9 +1381,8 @@ void scheduler_enqueue(struct scheduler *s, struct task *t) {
     if (qid >= s->nr_queues) error("Bad computed qid.");
 
     /* If no previous owner, pick a random queue. */
-    if (qid < 0)
-      qid = rand_r((unsigned int *)pthread_getspecific(s->local_seed_pointer)) %
-            s->nr_queues;
+    /* Note that getticks() is random enough */
+    if (qid < 0) qid = getticks() % s->nr_queues;
 
     /* Increase the waiting counter. */
     atomic_inc(&s->waiting);