NFSv4.1: Use layout credentials for get_deviceinfo calls

This is not strictly needed, since get_deviceinfo is not allowed to
return NFS4ERR_ACCESS or NFS4ERR_WRONG_CRED, but lets do it anyway
for consistency with other pNFS operations.

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

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

diff --cc fs/nfs/nfs4filelayout.c
Simple merge

diff --cc fs/nfs/nfs4filelayout.h
Simple merge

diff --cc fs/nfs/nfs4filelayoutdev.c
Simple merge

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

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

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