NFSv4.1/pnfs Improve the packing of struct pnfs_layout_hdr
NFSv4.1/pnfs Improve the packing of struct pnfs_layout_hdr

Eliminate a couple of holes in the structure, and move the 2 atomics
into the same cacheline.

Signed-off-by: Trond Myklebust <cc958843532c615cbd4920e868f78c7985331a5a@primarydata.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs