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>
void rtnl_register(int protocol, int msgtype,
		   rtnl_doit_func doit, rtnl_dumpit_func dumpit,
		   rtnl_calcit_func calcit)
{
	if (__rtnl_register(protocol, msgtype, doit, dumpit, calcit) < 0)
		panic("Unable to register rtnetlink message handler, "
		      "protocol = %d, message type = %d\n",
		      protocol, msgtype);
}

void rtnl_register(int protocol, int msgtype,
		   rtnl_doit_func doit, rtnl_dumpit_func dumpit,
		   rtnl_calcit_func calcit)
{
	if (__rtnl_register(protocol, msgtype, doit, dumpit, calcit) < 0)
		panic("Unable to register rtnetlink message handler, "
		      "protocol = %d, message type = %d\n",
		      protocol, msgtype);
}
