pid: unlock_irq when alloc_pid fails because init has exited.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/kernel/pid.c b/kernel/pid.c
index de9af60..f2c6a68 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -331,7 +331,7 @@
 	return pid;
 
 out_unlock:
-	spin_unlock(&pidmap_lock);
+	spin_unlock_irq(&pidmap_lock);
 out_free:
 	while (++i <= ns->level)
 		free_pidmap(pid->numbers + i);