with NFS.
We are moving responsibility for creating the vnode_pager object into
the filesystems which own the vnode, and this is one of the places
we have to cover.
We call vnode_create_vobject() directly because we own the vnode.
If we can get the size easily, pass it as an argument to save the
call to VOP_GETATTR() in vnode_create_vobject()