Since there's percentage calcution, multiply on 32bit variable
will cause overflow. So fix the variables as 64bit.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>