py: Fix casting and printing of small int.
diff --git a/py/objint.c b/py/objint.c
index b33557b..775e564 100644
--- a/py/objint.c
+++ b/py/objint.c
@@ -47,7 +47,7 @@
 
 void int_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
     if (MP_OBJ_IS_SMALL_INT(self_in)) {
-        print(env, "%d", (int)MP_OBJ_SMALL_INT_VALUE(self_in));
+        print(env, INT_FMT, MP_OBJ_SMALL_INT_VALUE(self_in));
     }
 }