Staging: comedi: __user markup on comedi_fops.c

Hm, what a mess.  I tried to properly mark up the __user pointers,
but for some of these structures, we use them both in the kernel,
and across the user/kernel boundry, which isn't ok.  So we end
up generating a few new sparse warnings in places we were not before,
but the large majority of things are now properly tagged in the fops
file.

The whole ioctl interface needs to be carefully looked at in the future.

Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>