CIFS: Fix cifs_writev_requeue when wsize changes

If wsize changes on reconnect we need to use new writedata structure
that for retrying.

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>