[Matrix]: fix a minor bug in resize of mem_vec_store.
[Matrix]: fix a minor bug in resize of mem_vec_store.

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