ip4defrag: add TODO about duplicate data handling
ip4defrag: add TODO about duplicate data handling

The current code doesn't handle the situation where we receive a
fragment that contains both duplicate and new data; add an explicit TODO
so that we can fix it later.

rouzier/gopacket,rouzier/gopacket,xuzhaokui/gopacket,google/gopacket,google/gopacket,rouzier/gopacket,xuzhaokui/gopacket,xuzhaokui/gopacket,google/gopacket