Staging: comedi: fix comments over 80 issue in usbduxfast.c

This is a patch to the usbduxfast.c file that fixes comments
over 80 warnings found by the checkpatch.pl tool

Signed-off-by: Stewart Robertson <stewart_r@aliencamel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>