NFSv4: Fix a nograce recovery hang

Since commit 5cae02f4

 an OPEN_CONFIRM should
have a privileged sequence in the recovery case to allow nograce recovery to
proceed for NFSv4.0.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>