staging: comedi: addi_apci_3501: don't read the unused PCI bars

This driver only uses PCI bar 0 and 1, don't bother reading the
unused PCI bars.

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