NFSv4: don't reprocess cached open CLAIM_PREVIOUS

Cached opens have already been handled by _nfs4_opendata_reclaim_to_nfs4_state
and can safely skip being reprocessed, but must still call update_open_stateid
to make sure that all active fmodes are recovered.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Cc: stable@vger.kernel.org # 3.7.x: f494a607: NFSv4: fix NULL dereference
Cc: stable@vger.kernel.org # 3.7.x: a43ec98b

: NFSv4: don't fail on missin
Cc: stable@vger.kernel.org # 3.7.x
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>