staging: comedi: ni_atmio: convert printk to dev_err in ni_getboardtype()

Convert these printk() messages to dev_err().

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>