Fix a build error when using the linux-4.8 headers that results in:
In file included from pppoe.h:87:0,
from plugin.c:29:
../usr/include/netinet/in.h:211:8: note: originally defined here
struct in6_addr
^~~~~~~~
In file included from ../usr/include/linux/if_pppol2tp.h:20:0,
from ../usr/include/linux/if_pppox.h:26,
from plugin.c:52:
../usr/include/linux/in6.h:49:8: error: redefinition of 'struct sockaddr_in6'
struct sockaddr_in6 {
^~~~~~~~~~~~
Signed-off-by: Jackie Huang <jackie.huang@windriver.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
