fix undefined variable when enabling ascii protocol
fix undefined variable when enabling ascii protocol

madcowswe/ODrive,madcowswe/ODriveFirmware,madcowswe/ODriveFirmware,madcowswe/ODriveFirmware,madcowswe/ODriveFirmware,madcowswe/ODrive,madcowswe/ODrive,madcowswe/ODrive,madcowswe/ODrive