staging: ozwpan: Replace existing event logging mechanism

This patch replaces existing event logging mechanism from ioctl to debugfs.
This patch replaces previous patch submitted by Chris Kelly. Previous patch can
be found at :-
http://article.gmane.org/gmane.linux.usb.general/60026/



Signed-off-by: Rupesh Gujare <rgujare@ozmodevices.com>
Signed-off-by: Chris Kelly <ckelly@ozmodevices.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>