dm: Use kzalloc for all structs with embedded biosets/mempools

[ Upstream commit d377535405686f735b90a8ad4ba269484cd7c96e ]

mempool_init()/bioset_init() require that the mempools/biosets be zeroed
first; they probably should not _require_ this, but not allocating those
structs with kzalloc is a fairly nonsensical thing to do (calling
mempool_exit()/bioset_exit() on an uninitialized mempool/bioset is legal
and safe, but only works if said memory was zeroed.)

Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/md/dm-bio-prison.c b/drivers/md/dm-bio-prison.c
index 03af174..fa2432a 100644
--- a/drivers/md/dm-bio-prison.c
+++ b/drivers/md/dm-bio-prison.c
@@ -32,7 +32,7 @@
  */
 struct dm_bio_prison *dm_bio_prison_create(void)
 {
-	struct dm_bio_prison *prison = kmalloc(sizeof(*prison), GFP_KERNEL);
+	struct dm_bio_prison *prison = kzalloc(sizeof(*prison), GFP_KERNEL);
 
 	if (!prison)
 		return NULL;