staging: comedi: das1800: use comedi_request_region()

Use comedi_request_region() to request the I/O region used by this
driver.

Remove the noise when the board is first attached as well as the
error message when the request_region() fails, comedi_request_reqion()
will output the error message if necessary.

This driver does a second request_region() for the additional I/O space
used on the 'ao' type boards. Modify the error message if that request
fails so it matches to format of the comedi_request_region() message.

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