smartdns: fix valgrind warnings.

src/dns_cache.c

@@ -408,6 +408,7 @@ int dns_cache_insert(struct dns_cache_key *cache_key, int ttl, int speed, int no
 		ttl = DNS_CACHE_TTL_MIN;
 	}
 
+	memset(&info, 0, sizeof(info));
 	info.hitnum = 3;
 	safe_strncpy(info.domain, cache_key->domain, DNS_MAX_CNAME_LEN);
 	info.qtype = cache_key->qtype;

src/dns_server.c

@@ -4077,7 +4077,8 @@ _dns_server_process_dns64_callback(struct dns_request *request, struct dns_reque
 			pthread_mutex_unlock(&child_request->ip_map_lock);
 			return DNS_CHILD_POST_FAIL;
 		}
-
+		memset(new_addr_map, 0, sizeof(struct dns_ip_address));
+		
 		new_addr_map->addr_type = DNS_T_AAAA;
 		addr_len = DNS_RR_AAAA_LEN;
 		memcpy(new_addr_map->ip_addr, dns_conf_dns_dns64.prefix, 16);