Hash :
855f0804
        
        Author :
  
        
        Date :
2018-08-09T14:47:17
        
      
dns-example: free result in getaddrinfo callback
According to evdns.c, the result not freed by libevent after
the callback runs:
evdns_getaddrinfo_gotresolve()
{
    ...
    data->user_cb(0, data->pending_result, data->user_data);
    data->pending_result = NULL;
    ...
}
To reproduce, build with -fsanitize=address, add -g to the getopt
list in dns-example.c like in the current commit and run
  dns-example -g google.com
Closes: #681 # cherry-picked