In dora there is no autotools-brokensep bbclass. So let's just
set the build directory to the source directory ourselves. I have
not built the package for dora though/
Poky dizzy is more strict with -I/usr/include and the old
tcpdump could pick-up "/usr/bin/pcap-config" from the host
and fail. Just upgrade to a newer version of tcpdump and be
done with it.