fsnotify: check to make sure all fsnotify bits are unique

This patch adds a check to make sure that all fsnotify bits are unique and we
cannot accidentally use the same bit for 2 different fsnotify event types.

Signed-off-by: Eric Paris <eparis@redhat.com>

diff --cc fs/notify/fsnotify.c
Simple merge

diff --cc include/linux/fsnotify_backend.h
Simple merge