bit fileid's in NFSv2 and NFSv3. Without this fix, invalid casting (and sign
extension) was creating problems for any fileid greater than 2^31.
We discovered this because we have test clusters with more than 2 billion
allocated files and 64-bit ino_t's (and friend structures).
Reviewed by: rmacklem
Approved by: zml (mentor)
MFC after: 2 weeks