Add a note in example as well, that last sector is used for metadata, so it don't provoke confusions.
Add a note in example as well, that last sector is used for metadata,
so it don't provoke confusions.

Noticed by:	Victor Sudakov <sudakov@sibptus.tomsk.ru>
MFC after:	2 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase