The configure script (for libdnet) seems to find <net/bpf.h>
and detect some BSD stuff.

The lidnet's Makefile wants to include eth-bsd.c, arp-bsd.c
and other BSD friends.

This seems to put a cork on it, and no BSD stuff appears anymore.
[at least on my system].

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>