staging: comedi: range.c: reformat ioctl handler comment

The unlocked_ioctl handler in "comedi_fops.c" calls a different function
to handle each supported ioctl command code.  Most of these have a block
comment indicating which command code it handles, a brief description,
and an informal description of the inputs and outputs.  These block
comments were formatted in various styles, but have been reformatted to
use the usual block comment style.

The block comment for the handler function for the `COMEDI_RANGEINFO`
ioctl code is in "range.c".  Reformat it to use the usual block command
style to match the others.  Reword it a bit for consistency.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>