mac80211: use eth_zero_addr() to clear mac address

Use eth_zero_addr() to clear mac address instead of memset().

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Link: https://lore.kernel.org/r/1596273158-24183-1-git-send-email-linmiaohe@huawei.com


Signed-off-by: Johannes Berg <johannes.berg@intel.com>