staging: comedi: pcl818: convert printk() messages to dev_{level}

Convert the remaining printk messsages in this driver to dev_{level}.

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>