freezer: task->exit_state should be treated as bolean

Except for BUG_ON() checks, we should not use EXIT_XXXX defines outside of
exit/wait paths.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/power/process.c

@@ -25,10 +25,9 @@
 
 static inline int freezeable(struct task_struct * p)
 {
-	if ((p == current) || 
+	if ((p == current) ||
 	    (p->flags & PF_NOFREEZE) ||
-	    (p->exit_state == EXIT_ZOMBIE) ||
-	    (p->exit_state == EXIT_DEAD))
+	    (p->exit_state != 0))
 		return 0;
 	return 1;
 }