Merge "ion: ensure valid start address"

/* Copyright (c) 2011-2017, The Linux Foundation. All rights reserved.

/* Copyright (c) 2011-2018, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

			data.flush_data.offset;

		end = start + data.flush_data.length;

		if (check_vaddr_bounds(start, end)) {

		if (start && check_vaddr_bounds(start, end)) {

			pr_err("%s: virtual address %pK is out of bounds\n",

			       __func__, data.flush_data.vaddr);

			ret = -EINVAL;