nfs4.1: Add SP4_MACH_CRED write and commit support

WRITE and COMMIT can use the machine credential.

If WRITE is supported and COMMIT is not, make all (mach cred) writes FILE_SYNC4.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --cc fs/nfs/nfs4_fs.h
Simple merge

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

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

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