sx8: use the internal state machine to check if del_gendisk needs to be called

Remove usage of the block layer internal GENHD_FL_UP by just looking
at the host state.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210809064028.1198327-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/sx8.c

@@ -1373,7 +1373,7 @@ static void carm_free_disk(struct carm_host *host, unsigned int port_no)
 	if (!disk)
 		return;
 
-	if (disk->flags & GENHD_FL_UP)
+	if (host->state > HST_DEV_ACTIVATE)
 		del_gendisk(disk);
 	blk_cleanup_disk(disk);
 }