[Matrix]: fix a mem bug in unit tests of local matrices.
[Matrix]: fix a mem bug in unit tests of local matrices.

flashxio/FlashX,flashxio/FlashX,icoming/FlashGraph,flashxio/FlashX,icoming/FlashGraph,flashxio/FlashX,icoming/FlashX,icoming/FlashX,icoming/FlashX,icoming/FlashGraph,icoming/FlashX,icoming/FlashGraph,icoming/FlashX,flashxio/FlashX,flashxio/FlashX,icoming/FlashGraph