nfsd4: fix spurious 4.1 post-reboot failures

In the NFSv4.1 case, this could cause a spurious "NFSD: failed to write
recovery record (err -17); please check that /var/lib/nfs/v4recovery
exists and is writable.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Reported-by: Steve Dickson <SteveD@redhat.com>