Remove old debugging tests.

They had their time and place, but right now they are using
infrastructure that is getting re-done, and we're better off
just dropping them.

kernel/exit.c

@@ -858,13 +858,6 @@ asmlinkage long sys_exit(int error_code)
 
 task_t fastcall *next_thread(const task_t *p)
 {
-#ifdef CONFIG_SMP
-	if (!p->sighand)
-		BUG();
-	if (!spin_is_locked(&p->sighand->siglock) &&
-				!rwlock_is_locked(&tasklist_lock))
-		BUG();
-#endif
 	return pid_task(p->pids[PIDTYPE_TGID].pid_list.next, PIDTYPE_TGID);
 }