ip6_deletefraghdr
if (ip6_deletefraghdr(m, offset, M_NOWAIT) != 0)
ip6_deletefraghdr(m, offset, M_NOWAIT);
int ip6_deletefraghdr(struct mbuf *, int, int);
if (ip6_deletefraghdr(m, hdrlen, M_NOWAIT) != 0)