staging: comedi: amplc_dio200_pci: remove 'mainsize' from PCI boardinfo

The 'mainsize' member in the boardinfo for the DIO200 PCI boards is only used
for a sanity check of the pci_resource_len(). This sanity check is not needed.

Remove the sanity check along with the 'mainsize' values in the boardinfo.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>