Make sure we don't roll over when rounding up to align the requested size.
BUG=chrome-os-partner:11642
TEST=none
No test; if security guys approve code change, it's fixed.
Change-Id: I2e915a6e6b37fc315ab7adb435e2fce4eed670ba
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/28729
Reviewed-by: Sumit Gwalani <sumitg@google.com>
Reviewed-by: Gaurav Shah <gauravsh@chromium.org>