staging: vt6655: use %pM for BSSID

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Forest Bond <forest@alittletooquiet.net>
Cc: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>