xen-blkfront: set max_discard/secure erase limits to UINT_MAX

Currently xen-blkfront set the max discard limit to the capacity of
the device, which is suboptimal when the capacity changes.  Just set
it to UINT_MAX, which has the same effect and is simpler.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Link: https://lore.kernel.org/r/20240221125845.3610668-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/xen-blkfront.c

@@ -944,20 +944,18 @@ static const struct blk_mq_ops blkfront_mq_ops = {
 static void blkif_set_queue_limits(struct blkfront_info *info)
 {
 	struct request_queue *rq = info->rq;
-	struct gendisk *gd = info->gd;
 	unsigned int segments = info->max_indirect_segments ? :
 				BLKIF_MAX_SEGMENTS_PER_REQUEST;
 
 	blk_queue_flag_set(QUEUE_FLAG_VIRT, rq);
 
 	if (info->feature_discard) {
-		blk_queue_max_discard_sectors(rq, get_capacity(gd));
+		blk_queue_max_discard_sectors(rq, UINT_MAX);
 		rq->limits.discard_granularity = info->discard_granularity ?:
 						 info->physical_sector_size;
 		rq->limits.discard_alignment = info->discard_alignment;
 		if (info->feature_secdiscard)
-			blk_queue_max_secure_erase_sectors(rq,
-							   get_capacity(gd));
+			blk_queue_max_secure_erase_sectors(rq, UINT_MAX);
 	}
 
 	/* Hard sector size and max sectors impersonate the equiv. hardware. */