NFSv4.1: Select the "most recent locking state" for read/write/setattr stateids

Follow the practice described in section 8.2.2 of RFC5661: When sending a
read/write or setattr stateid, set the seqid field to zero in order to
signal that the NFS server should apply the most recent locking state.

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

diff --cc fs/nfs/nfs4proc.c
Simple merge

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

diff --cc include/linux/nfs_fs_sb.h
Simple merge