media: mtk-vcodec: fix leaked of_node references

The call to of_find_device_by_node returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c:60:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 38, but without a corresponding object release within this function.
drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c:63:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 38, but without a corresponding object release within this function.
drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c:72:3-9: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 38, but without a corresponding object release within this function.
Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_pm.c

@@ -42,8 +42,8 @@ int mtk_vcodec_init_dec_pm(struct mtk_vcodec_dev *mtkdev)
 	}
 
 	pdev = of_find_device_by_node(node);
+	of_node_put(node);
 	if (WARN_ON(!pdev)) {
-		of_node_put(node);
 		return -1;
 	}
 	pm->larbvdec = &pdev->dev;