qcow2: Fix grow_refcount_table error handling

In case of failure, we haven't increased the refcount for the newly allocated
cluster yet. Therefore we must not free the cluster or its refcount will become
negative (and endless recursion is possible).
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

block/qcow2-refcount.c

@@ -182,7 +182,6 @@ static int grow_refcount_table(BlockDriverState *bs, int min_size)
     qcow2_free_clusters(bs, old_table_offset, old_table_size * sizeof(uint64_t));
     return 0;
  fail:
-    qcow2_free_clusters(bs, table_offset, new_table_size2);
     qemu_free(new_table);
     return -EIO;
 }