staging: comedi: ni_atmio: fix build error due to missing '; '

Fix a build error due to a missing ';' at the end of a line.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reported-by: Geert Uytterhoeven <geert.uytterhoeven@gmail.com>
Cc: Kumar Amit Mehta <gmate.amit@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>