We should use of_node_put() for the reference returned by
of_get_child_by_name() which has increased the refcount.

Fixes: 45721c40 ("can: rcar_canfd: Add support for r8a779a0 SoC")
Link: https://lore.kernel.org/all/20220712095623.364287-1-windhl@126.comSigned-off-by: Liang He <windhl@126.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>