nfsd4: cleanup seqid op stateowner usage

Now that the replay owner is in the cstate we can remove it from a lot
of other individual operations and further simplify
nfs4_preprocess_seqid_op().

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --cc fs/nfsd/nfs4state.c
Simple merge

diff --cc fs/nfsd/nfs4xdr.c
Simple merge

diff --cc fs/nfsd/xdr4.h
Simple merge