can: mscan: mpc5xxx_can: mpc5xxx_can_probe(): remove useless BUG_ON()

In the function mpc5xxx_can_probe(), the variable 'data' has already
been determined in the above code, so the BUG_ON() in this place is
useless, remove it.

Link: https://lore.kernel.org/r/20210823141033.17876-1-tangbin@cmss.chinamobile.com


Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>