message: use a constant value to define the debug level
diff: @@ -59,7 +59,7 @@ pub struct KernelLogger {
  }
  /// default logger to handle kernel messages
  -pub static LOGGER: KernelLogger = KernelLogger { log_level: LogLevel::Info };
  +pub const LOGGER: KernelLogger = KernelLogger { log_level: LogLevel::Info };
  macro_rules! printlog {
  