[R]: fix a bug in fg.topK.scan
[R]: fix a bug in fg.topK.scan

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