use mingw/msvc compatible printing of size_t

examples/client.c

@@ -196,7 +196,7 @@ int main(int argc, char *argv[]) {
     retval = UA_Client_call(client, UA_NODEID_NUMERIC(0, UA_NS0ID_OBJECTSFOLDER),
                             UA_NODEID_NUMERIC(1, 62541), 1, &input, &outputSize, &output);
     if(retval == UA_STATUSCODE_GOOD) {
-        printf("Method call was successfull, and %zu returned values available.\n", outputSize);
+        printf("Method call was successfull, and %Iu returned values available.\n", outputSize);
         UA_Array_delete(output, outputSize, &UA_TYPES[UA_TYPES_VARIANT]);
     } else {
         printf("Method call was unsuccessfull, and %x returned values available.\n", retval);