Because of two's complement reprensentation, casting an int to
and unsigned value doesn't simply get rid of the negative sign.
As such a value of -1 becomes 0xFFFFFFFF, which is clearly not
the desired effect.
This patch deals with cases when @cpu has the value of -1. In
those cases queue '0' is initially selected.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
c14318faac