block: make sure ->nr_integrity_segments is cloned in blk_rq_prep_clone

Make sure ->nr_integrity_segments is cloned in blk_rq_prep_clone(),
otherwise requests cloned by device-mapper multipath will not have the
proper nr_integrity_segments values set, then BUG() is hit from
sg_alloc_table_chained().

Fixes: b0fd271 ("block: add request clone interface (v2)")
Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20250310115453.2271109-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Ming Lei

block/blk-mq.c

@@ -3314,6 +3314,7 @@ int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 		rq->special_vec = rq_src->special_vec;
 	}
 	rq->nr_phys_segments = rq_src->nr_phys_segments;
+	rq->nr_integrity_segments = rq_src->nr_integrity_segments;
 
 	if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0)
 		goto free_and_out;