Upgrade libpcap to 1.10.4

libpcap/pcap-nit.c

@@ -125,6 +125,9 @@ pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 	 * Loop through each packet.  The increment expression
 	 * rounds up to the next int boundary past the end of
 	 * the previous packet.
+	 *
+	 * This assumes that a single buffer of packets will have
+	 * <= INT_MAX packets, so the packet count doesn't overflow.
 	 */
 	n = 0;
 	ep = bp + cc;