Revert "nfsd: cut the Linux NFSv4.1/4.2 some slack w.r.t. RFC5661"

This reverts commit 9edaceca8165e2864267547311daf145bb520270.

It turns out that the Linux client intentionally does an NFSv4.1
RPC with only a Sequence operation in it and with "seqid + 1"
for the slot. This is used to re-synchronize the slot's seqid
and the client expects the NFS4ERR_SEQ_MISORDERED error reply.

As such, revert the patch, so that the server remains RFC5661
compliant.