remoteproc: rcar_rproc: Call of_node_put() on iteration error

Function of_phandle_iterator_next() calls of_node_put() on the last
device_node it iterated over, but when the loop exits prematurely it has
to be called explicitly.

Fixes: 285892a7

 ("remoteproc: Add Renesas rcar driver")
Cc: stable@vger.kernel.org
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20230320221826.2728078-4-mathieu.poirier@linaro.org
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>