Memory leak in Libnet

Hi Mike,

It seems the following "strdup" is a memory leak

libnet-1.1.2:

[libnet_if_addr.c]
    238
    239         if ((al->device = strdup(device)) == NULL)
    240         {
    241             snprintf(errbuf, LIBNET_ERRBUF_SIZE,
    242                     "%s(): strdup not enough memory\n", __func__);
    243             return(-1);
    244         }


Should we do a "free" before each strdup() except when al->device 
is NULL ?

Thanks

Kevin