NFSv4: Don't ask for the change attribute when reclaiming state

We don't need to ask for the change attribute when returning a delegation
or recovering from a server reboot, and it could actually cause us to
obtain an incorrect value if we're using a pNFS flavour that requires
LAYOUTCOMMIT.

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