fixing a bug in CPU Adam and Adagrad (#3109)
Co-authored-by: Bing Xie <bingxie@BINGHYPC014.redmond.corp.microsoft.com>
Co-authored-by: Shaden Smith <Shaden.Smith@microsoft.com>
Co-authored-by: Olatunji Ruwase <olruwase@microsoft.com>
Co-authored-by: Jeff Rasley <jerasley@microsoft.com>
