The index is signed, make sure it is not negative
when we read the array element.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>