crypto: hisilicon/debugfs - Fix the processing logic issue in the debugfs creation

There is a scenario where the file directory is created but the
file attribute is not set. In this case, if a user accesses the
file, an error occurs.

So adjust the processing logic in the debugfs creation to
prevent the file from being accessed before the file attributes
such as the index are set.

Signed-off-by: Chenghai Huang <huangchenghai2@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>