use only UA_malloc internally (2nd pass)

src/client/ua_client.c

@@ -47,7 +47,7 @@ static void UA_Client_deleteMembers(UA_Client* client) {
     UA_Client_NotificationsAckNumber *n, *tmp;
     LIST_FOREACH_SAFE(n, &client->pendingNotificationsAcks, listEntry, tmp) {
         LIST_REMOVE(n, listEntry);
-        free(n);
+        UA_free(n);
     }
     UA_Client_Subscription *sub, *tmps;
     LIST_FOREACH_SAFE(sub, &client->subscriptions, listEntry, tmps)