can: m_can: use consistent indention

The driver uses indent-with-tab for defines. Replace spaces after
IR_ERR_BUS_31X with tab for consistent indention.

Link: https://lore.kernel.org/all/20221024185544.68240-1-mkl@pengutronix.deSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>