soc: mediatek: mtk-svs: Call of_node_put(np) only once in svs_get_subsys_device()

soc: mediatek: mtk-svs: Call of_node_put(np) only once in svs_get_subsys_device()

An of_node_put(np) call was immediately used after a pointer check
for a of_find_device_by_node() call in this function implementation.
Thus call such a function only once instead directly before the check.

This issue was transformed by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/884f0a5d-e6d3-47dc-8a9e-201bb86b271f@web.de
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>