staging: comedi: amplc_pci230: tidy up irq request

Clean up the irq request in the attach of this driver and remove the
dev_{level} noise.

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>