staging: wlags49_h2: remove useless DbgHwAddr() method

There is no needs to prepare string for MAC addresses beforehand, due to
kernel's *printf() have '%pM' format option.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>