block: cleanup the !zoned case in blk_revalidate_disk_zones

blk_revalidate_disk_zones is never called for non-zoned devices.  Just
return early and warn instead of trying to handle this case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-zoned.c

@@ -520,6 +520,9 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 	sector_t sector = 0;
 	int ret = 0;
 
+	if (WARN_ON_ONCE(!blk_queue_is_zoned(q)))
+		return -EIO;
+
 	/*
 	 * BIO based queues do not use a scheduler so only q->nr_zones
 	 * needs to be updated so that the sysfs exposed value is correct.
@@ -535,10 +538,8 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 	 */
 	noio_flag = memalloc_noio_save();
 
-	if (!blk_queue_is_zoned(q) || !nr_zones) {
-		nr_zones = 0;
+	if (!nr_zones)
 		goto update;
-	}
 
 	/* Allocate bitmaps */
 	ret = -ENOMEM;