NFS: Get suppattr_exclcreat when getting server capabilities

Create file with attributs as NFS4_CREATE_EXCLUSIVE4_1 mode
depends on suppattr_exclcreat attribut.

v3, same as v2.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

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

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

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

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