can: j1939: fix checkpatch warnings

This patch fixes a checkpatch warning about a long line and wrong
indention.

Cc: Robin van der Gracht <robin@protonic.nl>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/r/20210616102811.2449426-2-mkl@pengutronix.de


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>