[PATCH] release_task: replace open-coded ptrace_unlink()

Use ptrace_unlink() instead of open-coding.  No changes in kernel/exit.o
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/exit.c

@@ -73,8 +73,7 @@ void release_task(struct task_struct * p)
 	spin_lock(&p->proc_lock);
 	proc_dentry = proc_pid_unhash(p);
 	write_lock_irq(&tasklist_lock);
-	if (unlikely(p->ptrace))
-		__ptrace_unlink(p);
+	ptrace_unlink(p);
 	BUG_ON(!list_empty(&p->ptrace_list) || !list_empty(&p->ptrace_children));
 	__exit_signal(p);
 	/*