bio-integrity: Fix use of bs->bio_integrity_pool after free

This fixes a copy and paste error introduced by 9f060e22
("block: Convert integrity to bvec_alloc_bs()").

Found by Coverity (CID 1020654).
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/bio-integrity.c

@@ -734,7 +734,7 @@ void bioset_integrity_free(struct bio_set *bs)
 		mempool_destroy(bs->bio_integrity_pool);
 
 	if (bs->bvec_integrity_pool)
-		mempool_destroy(bs->bio_integrity_pool);
+		mempool_destroy(bs->bvec_integrity_pool);
 }
 EXPORT_SYMBOL(bioset_integrity_free);