inotify: tail drop inotify q_overflow events

In f44aebcc the tail drop logic of events with no file backing
(q_overflow and in_ignored) was reversed so IN_IGNORED events would
never be tail dropped. This now means that Q_OVERFLOW events are NOT
tail dropped. The fix is to not tail drop IN_IGNORED, but to tail drop
Q_OVERFLOW.

Signed-off-by: Eric Paris <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

fs/notify/notification.c

···
 				return true;
 			break;
 		case (FSNOTIFY_EVENT_NONE):
+			if (old->mask & FS_Q_OVERFLOW)
+				return true;
+			else if (old->mask & FS_IN_IGNORED)
+				return false;
 			return false;
 		};
 	}