nfs4: simplify data types fattr4_{files,space} and Co.

the next portion of attribute simplification

Acked-by: Gerd Behrmann
Target: master
nfs4: fix nfstime4 encoding

fix copy-paste regression introduced in 45f0a62

Acked-by: Paul Millar
Target: master
nfs4: simplify bitmap4

use int instead of uint32_t

Acked-by: Gerd Behrmann
Target: master