fixed buf: wrong length when pull data from arp_queue

Signed-off-by: jason-foo <fujianshuang@gmail.com>
fixed buf: wrong length when demultiplexing

Signed-off-by: jason-foo <fujianshuang@gmail.com>
changed output format

Signed-off-by: jason-foo <fujianshuang@gmail.com>
added dev_xmit_init() and moved opening sockaddr_ll to it

Signed-off-by: jason-foo <fujianshuang@gmail.com>
clear padding data when ethernet packet is too short

Signed-off-by: jason-foo <fujianshuang@gmail.com>
updated README

Signed-off-by: jason-foo <fujianshuang@gmail.com>