[Matrix]: remove unnecessary check in unit test of dense matrix.
[Matrix]: remove unnecessary check in unit test of dense matrix.

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