the PR is about inclusion of FCS into bpf_mtap().
	what should device driver writer do on bpf_mtap() when the device is
	marked with M_HASFCS?
		bpf_mtap(ifp->if_bpf, m);
	will include the FCS into bpf output.
		m_adj(m, -4);
		bpf_mtap(ifp->if_bpf, m);
	will solve the problem, but m_adj() is done in sys/net/if_ethersubr.c
	as well, so it is not appropriate.
	if m->m_next is NULL,
		m->m_len -= 4;
		bpf_mtap(ifp->if_bpf, m);
		m->m_len += 4;
	should work, but for jumbo (9K) packet it does not work.

itojun