NFS: Fix stateid used for NFS v4 closes

After 566fcec6 the client uses the "current stateid" from the
nfs4_state structure to close a file.  This could potentially contain a
delegation stateid, which is disallowed by the protocol and causes
servers to return NFS4ERR_BAD_STATEID.  This patch restores the
(correct) behavior of sending the open stateid to close a file.

Reported-by: Olga Kornievskaia <kolga@netapp.com>
Fixes: 566fcec6 (NFSv4: Fix an atomicity problem in CLOSE)
Signed-off-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>