Start doing VTOC validation before using its contents.
The validation is adjusted so as not to break existing setups
that do not set the VTOC version, sanity and partition count entries.
VTOC tables with more than 8 partitions will NOT be used.
Signed-off-by: NMark Fortescue <mark@mtfhpc.demon.co.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!