zram: replace fsync_bdev with sync_blockdev

When calling fsync_bdev(), zram driver guarantees that the bdev won't be
opened by anyone, then there can't be one active fs/superblock over the
zram bdev, so replace fsync_bdev with sync_blockdev.
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Link: https://lore.kernel.org/r/20211025025426.2815424-5-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/zram/zram_drv.c

@@ -1790,7 +1790,7 @@ static ssize_t reset_store(struct device *dev,
 	mutex_unlock(&bdev->bd_disk->open_mutex);
 
 	/* Make sure all the pending I/O are finished */
-	fsync_bdev(bdev);
+	sync_blockdev(bdev);
 	zram_reset_device(zram);
 
 	mutex_lock(&bdev->bd_disk->open_mutex);
@@ -1995,7 +1995,7 @@ static int zram_remove(struct zram *zram)
 		;
 	} else {
 		/* Make sure all the pending I/O are finished */
-		fsync_bdev(bdev);
+		sync_blockdev(bdev);
 		zram_reset_device(zram);
 	}