staging: unisys: visorbus: fix visorchannel.c comments

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

Comments were fixed in visorchannel.c:
* All functions worthy of documenting now use standard kerneldoc
  formatting.
* Multi-line comments were tweaked so as to use appropriate conventions.
* 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>
Signed-off-by: David Binder <david.binder@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>