staging: unisys: Fix visorchannel.c block comments

This patch fixes the last checkpatch warning about:
Block comments use a trailing */ on a separate line

Signed-off-by: Erik Arfvidson <erik.arfvidson@unisys.com>
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>