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

[ Upstream commit 07bfd9bdf568a38d9440c607b72342036011f727 ]

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>