[media] exynos4-is: Add missing 'of_node_put'

It is likely that a "of_node_put(ep)" is missing here.
There is one in the previous error handling code, and one a few lines
below in the normal case as well.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/exynos4-is/media-dev.c

@@ -402,8 +402,10 @@ static int fimc_md_parse_port_node(struct fimc_md *fmd,
 		return ret;
 	}
 
-	if (WARN_ON(endpoint.base.port == 0) || index >= FIMC_MAX_SENSORS)
+	if (WARN_ON(endpoint.base.port == 0) || index >= FIMC_MAX_SENSORS) {
+		of_node_put(ep);
 		return -EINVAL;
+	}
 
 	pd->mux_id = (endpoint.base.port - 1) & 0x1;