Fix tsk->exit_state usage

tsk->exit_state can only be 0, EXIT_ZOMBIE, or EXIT_DEAD.  A non-zero test
is the same as tsk->exit_state & (EXIT_ZOMBIE | EXIT_DEAD), so just testing
tsk->exit_state is sufficient.

Signed-off-by: Eugene Teo <eugeneteo@kernel.sg>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/sched.c b/kernel/sched.c
index 72a809a..9d45850 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5279,7 +5279,7 @@
 	struct rq *rq = cpu_rq(dead_cpu);
 
 	/* Must be exiting, otherwise would be on tasklist. */
-	BUG_ON(p->exit_state != EXIT_ZOMBIE && p->exit_state != EXIT_DEAD);
+	BUG_ON(!p->exit_state);
 
 	/* Cannot have done final schedule yet: would have vanished. */
 	BUG_ON(p->state == TASK_DEAD);