#ifdef POSIX changed to #ifdef WITH_POSIX (allows attribs to be freed)

resource.c

@@ -409,7 +409,7 @@ coap_delete_attr(coap_attr_t *attr) {
     coap_free(attr->name.s);
   if (attr->flags & COAP_ATTR_FLAGS_RELEASE_VALUE)
     coap_free(attr->value.s);
-#ifdef POSIX
+#ifdef WITH_POSIX
   coap_free(attr);
 #endif
 #ifdef WITH_LWIP