This makes cp_new_stat() a bit more readable, and avoids having to
memset() the whole structure just to fill in a couple of padding fields.
This is another result of me looking at code generation of functions
that show up high on certain kernel profiles, and just going "Oh, let's
just clean that up".
Architectures that don't supply the #define to fill just the padding
fields will still fall back to memset().
* stat-cleanups:
vfs: don't force a big memset of stat data just to clear padding fields
vfs: de-crapify "cp_new_stat()" function