attempt to fix compiler warning relative to potential misaligned data access

/*

 * Curl_printable_address() returns a printable version of the 1st address

 * given in the 'ip' argument. The result will be stored in the buf that is

 * given in the 'ai' argument. The result will be stored in the buf that is

 * bufsize bytes big.

 *

 * If the conversion fails, it returns NULL.

 */

const char *Curl_printable_address(const Curl_addrinfo *ip,

                                   char *buf, size_t bufsize)

const char *

Curl_printable_address(const Curl_addrinfo *ai, char *buf, size_t bufsize)

{

  const void *ip4 = &((const struct sockaddr_in*)ip->ai_addr)->sin_addr;

  int af = ip->ai_family;

#ifdef CURLRES_IPV6

  const void *ip6 = &((const struct sockaddr_in6*)ip->ai_addr)->sin6_addr;

#else

  const void *ip6 = NULL;

  struct sockaddr_in *sa4;

  struct in_addr *ipaddr4;

#ifdef ENABLE_IPV6

  struct sockaddr_in6 *sa6;

  struct in6_addr *ipaddr6;

#endif

  return Curl_inet_ntop(af, af == AF_INET ? ip4 : ip6, buf, bufsize);

  switch (ai->ai_family) {

    case AF_INET:

      sa4 = (struct sockaddr_in *)ai->ai_addr;

      ipaddr4 = &sa4->sin_addr;

      return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr4, buf, bufsize);

#ifdef ENABLE_IPV6

    case AF_INET6:

      sa6 = (struct sockaddr_in6 *)ai->ai_addr;

      ipaddr6 = &sa6->sin6_addr;

      return Curl_inet_ntop(ai->ai_family, (const void *)ipaddr6, buf, bufsize);

#endif

    default:

      break;

  }

  return NULL;

}

/*