of: remove redundant memset in overlay

memset in of_build_overlay_info is redundant, the ovinfo has been
zeroed in of_fill_overlay_info when error.
Signed-off-by: YiPing Xu <xuyiping@hisilicon.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of/overlay.c

@@ -313,7 +313,6 @@ static int of_build_overlay_info(struct of_overlay *ov,
 
 	cnt = 0;
 	for_each_child_of_node(tree, node) {
-		memset(&ovinfo[cnt], 0, sizeof(*ovinfo));
 		err = of_fill_overlay_info(ov, node, &ovinfo[cnt]);
 		if (err == 0)
 			cnt++;