incorrect response time calculated

When the watched server also act as a client, tcprstat may get wrong response time.

example:
tcprstat -l host1 -p 3306 -n 0 -t 1

if host1 also act as a client, do some communicate to a remote server on port 3306, wrong response time may be calculated.

suggested fix:

int
process_ip(pcap_t *dev, const struct ip *ip, struct timeval tv) {
    char src[16], dst[16], *addr;
    int incoming;
    unsigned len;

    addr = inet_ntoa(ip->ip_src);
    strncpy(src, addr, 15);
    src[15] = '\0';

    addr = inet_ntoa(ip->ip_dst);
    strncpy(dst, addr, 15);
    dst[15] = '\0';

    if (is_local_address(ip->ip_src))
        incoming = 0;
    else if (is_local_address(ip->ip_dst))
        incoming = 1;
    else
        return 1;

when judge a packet as inbound or outbound package, add local port:

    if (is_local_address(ip->ip_src) and src_port == 3306)
        incoming = 0;
    else if (is_local_address(ip->ip_dst) and dst_port == 3306 )
        incoming = 1;