This flag gives CIFS the ability to support its native rename semantics.

Implementation is simple: just bail out before trying to hack around the
noreplace semantics.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Cc: Steve French <smfrench@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>