This is a prep rename patch for subsequent patches to generalize file
registration.

[io_uring_rsrc_update:: rename fds -> data]
Reviewed-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NBijan Mottahedeh <bijan.mottahedeh@oracle.com>
[leave io_uring_files_update as struct]
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>