XXX THIS CODE IS SERIOUSLY BROKEN! MSCP DEVICES ARE BLOCK I/O DEVICES,
AND THUS SPLBIO SHOULD BLOCK THEIR INTERRUPTS. The VAX port really
needs to get virtualized spl*() levels.
the number of partitions is > OLDMAXPARTITIONS. This is better
than silently truncating the label (don't want to silently throw
away partitions when using an old disklabel binary on a label with
> 8 partitions). From Enami Tsugutomo.
