dm: adjust structure members to improve alignment

Eliminate most holes in DM data structures that were modified by
commit 6f1c819c21 ("dm: convert to bioset_init()/mempool_init()").
Also prevent structure members from unnecessarily spanning cache
lines.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

drivers/md/dm-zoned-target.c

@@ -52,9 +52,9 @@ struct dmz_target {
 	struct dmz_reclaim	*reclaim;
 
 	/* For chunk work */
-	struct mutex		chunk_lock;
 	struct radix_tree_root	chunk_rxtree;
 	struct workqueue_struct *chunk_wq;
+	struct mutex		chunk_lock;
 
 	/* For cloned BIOs to zones */
 	struct bio_set		bio_set;