[ALPS05390740] ION: fix handle ref overflow issue

[PATCH] staging: android: ion: check for kref overflow

--This patch is against 4.4. It does not apply to master due to a large
--rework of ion in 4.12 which removed the affected functions altogther.
--4c23cbff ("staging: android: ion: Remove import interface")

Userspace can cause the kref to handles to increment
arbitrarily high. Ensure it does not overflow.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MTK-Commit-Id: 6196e0f8ef02b1d9a1fee7246dc2ce813abeb7c7

Change-Id: I48f744000aff109743ced3a3a40f8d259e169499
Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com>
CR-Id: ALPS05390740
Feature: ION
(cherry picked from commit 1d52b8d305de9b9ca1705636e9d31c9dd33ebfef)