staging: comedi: comedilib.h: Coding style warning fix for block comments

This patch is to comedilib.h file that fixes up following warnings
reported by checkpatch.pl :
I) Block comments use * on subsequent lines.

Apart from it I have remove header file path by base file name as
suggested by community.

Signed-off-by: Jitendra Kumar Khasdev <jkhasdev@gmail.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>