staging: comedi: remove unneeded semicolon

There is no need for ';' after '}'. This minor fix was suggested by
coccinelle.

Signed-off-by: Teodora Baluta <teobaluta@gmail.com>
Reviewed-by: Lisa Nguyen <lisa@xenapiadmin.com>
Reviewed-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>