[Note: this patch can be preserved or squashed into commit
  replace sdb.c with new library-based code
at the maintainer's best choice]

My initial code assumed the vendor is always VID_CERN, but this is
not true: some cells we use are VID_GSI.  This takes care of the thing.

To save a little space, instead of adding a 64-bit field to the data
structure describing a device, I add an integer field stating whether
the device is CERN or GSI.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>