linux-phytec-fsl

NFS: Create a common nfs_pageio_ops struct

At this point the read and write structures look identical, so combine
them into something shared by both.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>