[PATCH] NFS: Allow NFS versions to support different sets of inode operations.

 ACL support will require supporting additional inode operations in v4
 (getxattr, setxattr, listxattr).  This patch allows different protocol versions
 to support different inode operations by adding a file_inode_ops to the
 nfs_rpc_ops (to match the existing dir_inode_ops).

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>