crypto: pcrypt - Fix user-after-free on module unload

stable inclusion
from linux-4.19.102
commit 47ef5cb878817127bd3d54c3578bbbd3f7c2bf2c
CVE: NA

-------------------------------

[ Upstream commit 07bfd9bd ]

On module unload of pcrypt we must unregister the crypto algorithms
first and then tear down the padata structure.  As otherwise the
crypto algorithms are still alive and can be used while the padata
structure is being freed.

Fixes: 5068c7a8 ("crypto: pcrypt - Add pcrypt crypto...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lu Jialin <lujialin4@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: Wang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: Laibin Qiu <qiulaibin@huawei.com>