update native_uart implementation

Author: microdev1

shared-bindings/busio/UART.c

@@ -145,8 +145,8 @@ STATIC mp_obj_t busio_uart_make_new(const mp_obj_type_t *type, size_t n_args, co
 
 
 // Helper to ensure we have the native super class instead of a subclass.
-busio_uart_obj_t* native_uart(mp_obj_t uart_obj) {
-    mp_obj_t native_uart = mp_instance_cast_to_native_base(uart_obj, &busio_uart_type);
+busio_uart_obj_t *native_uart(mp_obj_t uart_obj) {
+    mp_obj_t native_uart = mp_obj_cast_to_native_base(uart_obj, &busio_uart_type);
     if (native_uart == MP_OBJ_NULL) {
         mp_raise_ValueError_varg(translate("Must be a %q subclass."), MP_QSTR_UART);
     }