staging: comedi: drivers: use dev->board_name in request_irq()

Most of the comedi drivers use the dev->board_name for the id string
passed to request_irq(). Fix the couple that still pass something
else.

Also, propogate the errno from request_irq().

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>