staging: comedi: daqboard2000: cleanup "find pci device" code

The "find pci device" code for this driver was quite a bit
different from the other comedi pci drivers. Clean it up so
it follows the format of the other drivers.

Use for_each_pci_dev() instead of open-coding the loop using
pci_get_device().

Check for a specific bus/slot then the vendor/device ids.

The loop checking for the matching boardinfo was creating an
"id" based on the subsystem_device and subsystem_vendor info
from the pci_dev. The vendor id was already checked so just
check against the subsystem_device.

Only return the pci_dev if a matching boardinfo is found.

Consolidate the dev_err messages when a device is not found
into a single message.

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>