Fix compiler warning in setsockopt().

ares_process.c

@@ -746,13 +746,13 @@ static int configure_socket(int s, ares_channel channel)
   /* Set the socket's send and receive buffer sizes. */
   if ((channel->socket_send_buffer_size > 0) &&
       setsockopt(s, SOL_SOCKET, SO_SNDBUF,
-                 &channel->socket_send_buffer_size,
+                 (const void*)&channel->socket_send_buffer_size,
                  sizeof(channel->socket_send_buffer_size)) == -1)
     return -1;
 
   if ((channel->socket_receive_buffer_size > 0) &&
       setsockopt(s, SOL_SOCKET, SO_RCVBUF,
-                 &channel->socket_receive_buffer_size,
+                 (const void*)&channel->socket_receive_buffer_size,
                  sizeof(channel->socket_receive_buffer_size)) == -1)
     return -1;
 
@@ -784,7 +784,8 @@ static int open_tcp_socket(ares_channel channel, struct server_state *server)
    * isn't very interesting in general.
    */
   opt = 1;
-  if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)) == -1)
+  if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY,
+                 (const void*)&opt, sizeof(opt)) == -1)
     {
        close(s);
        return -1;