NFSv4.1: send zero stateid seqid on v4.1 i/o

Data servers require a zero stateid seqid, and there is no advantage to not
doing the same for all NFSv4.1

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>