staging: unisys: visorbus: fix visorbus_private.h comments

This patch ONLY touches comment lines, i.e., NO executable code is
affected.

Comments were fixed in visorbus_private.h:
* Minor typos were corrected.
* Useless comments were removed.

Signed-off-by: Tim Sell <Timothy.Sell@unisys.com>
Signed-off-by: David Kershner <david.kershner@unisys.com>
Acked-By: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>