block: fix the count of PGPGOUT for WRITE_SAME

The vm counters is counted in sectors, so we should do the conversation
in submit_bio.

Fixes: 74d46992 ("block: replace bi_bdev with a gendisk pointer and partitions index")
Cc: stable@vger.kernel.org
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

block/blk-core.c

@@ -2434,7 +2434,7 @@ blk_qc_t submit_bio(struct bio *bio)
 		unsigned int count;
 
 		if (unlikely(bio_op(bio) == REQ_OP_WRITE_SAME))
-			count = queue_logical_block_size(bio->bi_disk->queue);
+			count = queue_logical_block_size(bio->bi_disk->queue) >> 9;
 		else
 			count = bio_sectors(bio);