Free a UDP packet vector (array of packets).
void SDLNet_FreePacketV(UDPpacket **packetV);
the results of a call to SDLNet_AllocPacketV().
This frees the results of a previous call to SDLNet_AllocPacketV(), freeing both the set of packets and the array that holds them.
It is safe to free a NULL array through here; it's a harmless no-op.
You must not use this to free packets allocated through any function other than SDLNet_AllocPacketV().
This function is available since SDL_net 2.0.0.