staging: rtl8192e: prefer using eth_broadcast_addr()

Prefer using the eth_broadcast_addr() instead of memset to broadcast
address 0xFF to the array.

Signed-off-by: Hari Prasath Gujulan Elango <hgujulan@visteon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>