make do_notify_parent() return bool

- change do_notify_parent() to return a boolean, true if the task should
  be reaped because its parent ignores SIGCHLD.

- update the only caller which checks the returned value, exit_notify().

This temporary uglifies exit_notify() even more, will be cleanuped by
the next change.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/exit.c b/kernel/exit.c
index d49134a..34d135f 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -820,6 +820,7 @@
 static void exit_notify(struct task_struct *tsk, int group_dead)
 {
 	int signal;
+	bool autoreap;
 	void *cookie;
 
 	/*
@@ -858,9 +859,11 @@
 
 	signal = tracehook_notify_death(tsk, &cookie, group_dead);
 	if (signal >= 0)
-		signal = do_notify_parent(tsk, signal);
+		autoreap = do_notify_parent(tsk, signal);
+	else
+		autoreap = (signal == DEATH_REAP);
 
-	tsk->exit_state = signal == DEATH_REAP ? EXIT_DEAD : EXIT_ZOMBIE;
+	tsk->exit_state = autoreap ? EXIT_DEAD : EXIT_ZOMBIE;
 
 	/* mt-exec, de_thread() is waiting for group leader */
 	if (unlikely(tsk->signal->notify_count < 0))
@@ -868,7 +871,7 @@
 	write_unlock_irq(&tasklist_lock);
 
 	/* If the process is dead, release it - nobody will wait for it */
-	if (signal == DEATH_REAP)
+	if (autoreap)
 		release_task(tsk);
 }