staging: comedi: ni_labpc_isadma: remove hard coded samples size

Use the comedi_bytes_per_sample() helper and remove the hard coded sample
size.

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>
1 file changed