replace thread_mlfqs checks in priority calculations with assertions

src/threads/thread.c

@@ -474,11 +474,7 @@ thread_recalculate_priority (void)
 {
   struct thread *t = thread_current ();
 
-  if (thread_mlfqs)
-  {
-    t->priority = calculate_bsd_priority (t->recent_cpu, t->nice);
-    return;
-  }
+  ASSERT(!thread_mlfqs)
 
   enum intr_level old_level = intr_disable ();
   t->priority = t->base_priority;
@@ -732,6 +728,9 @@ thread_schedule_tail (struct thread *prev)
 static int
 calculate_bsd_priority (fp32_t recent_cpu, int nice)
 {
+
+  ASSERT(thread_mlfqs);
+
   int priority = PRI_MAX - (fp_round (recent_cpu) / 4) - (nice * 2);
   if (priority < PRI_MIN)
     return PRI_MIN;