NFSv4: Declare the size up to date after it was set.

When we've changed the file size, then ensure we declare it to be
up to date in the inode attributes.

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