Nikkei edges up; caution over earnings, Ukraine caps gains

* Nikkei falls short of testing Monday's 2-week high * Yaskawa Elec tumbles after guidance disappoints * Investors awaiting upcoming earnings season * Ukraine tensions keep some investors on edge By Hideyuki Sano TOKYO, April 22 (Reuters) - Japanese shares advanced on Tuesday, taking heart from a solid session on Wall Street, but gains were limited below the two-week intraday high marked the previous day on caution over upcoming earnings reports and tensions in Ukraine.