[linux-cifs-client] fcntl method for file_operations

[Steve French]

> the NFS developers have submitted a patch which adds an fcntl() method
> to the file_operations structure.

This patch should be helpful to the cifs vfs for a different reason
(than the original NFS conflict between O_DIRECT/O_APPEND) , it will
allow a way to get directory change notification F_NOTIFY (and file open
notification, F_SETLEASE, perhaps) sent across the network (currenty
many fcntl calls are meaningful for local filesystems only).