dm exception store: fix failed set_chunk_size error path

Properly close the device if failing because of an invalid chunk size.

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 556acff..e5de762 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -251,7 +251,7 @@
 
 	r = set_chunk_size(tmp_store, argv[2], &ti->error);
 	if (r)
-		goto bad_cow;
+		goto bad_ctr;
 
 	r = type->ctr(tmp_store, 0, NULL);
 	if (r) {