rtnl: fix info leak on RTM_GETLINK request for VF devices

Initialize the mac address buffer with 0 as the driver specific function
will probably not fill the whole buffer. In fact, all in-kernel drivers
fill only ETH_ALEN of the MAX_ADDR_LEN bytes, i.e. 6 of the 32 possible
bytes. Therefore we currently leak 26 bytes of stack memory to userland
via the netlink interface.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
{
	const struct rtnl_link_ops *ops;

	list_for_each_entry(ops, &link_ops, list) {
		if (!strcmp(ops->kind, kind))
			return ops;
	}
	return NULL;
}

static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
{
	const struct rtnl_link_ops *ops;

	list_for_each_entry(ops, &link_ops, list) {
		if (!strcmp(ops->kind, kind))
			return ops;
	}
	return NULL;
}
