crypto: nx - fix nx_crypto_ctx_exit argument

crypto: nx - fix nx_crypto_ctx_exit argument

nx_crypto_ctx_shash_exit calls nx_crypto_ctx_exit with crypto_shash_ctx(...)
but crypto_shash_ctx gives a nx_crypto_ctx *, not a crypto_tfm *.

Fix the type in nx_crypto_ctx_exit and drop the bogus crypto_tfm_ctx
call.

This fixes the following oops:

  BUG: Unable to handle kernel data access at 0xc0403effffffffc8
  Faulting instruction address: 0xc000000000396cb4
  Oops: Kernel access of bad area, sig: 11 [#15]
  Call Trace:
   nx_crypto_ctx_shash_exit+0x24/0x60
   crypto_shash_exit_tfm+0x28/0x40
   crypto_destroy_tfm+0x98/0x140
   crypto_exit_ahash_using_shash+0x20/0x40
   crypto_destroy_tfm+0x98/0x140
   hash_release+0x1c/0x30
   alg_sock_destruct+0x38/0x60
   __sk_destruct+0x48/0x2b0
   af_alg_release+0x58/0xb0
   __sock_release+0x68/0x150
   sock_close+0x20/0x40
   __fput+0x110/0x3a0
   sys_close+0x48/0xa0
   system_call_exception+0x140/0x2d0
   system_call_common+0xf4/0x258

.. which came from hardlink(1) opportunistically using AF_ALG.

The same problem exists with nx_crypto_ctx_skcipher_exit getting a context
it wasn't expecting, but apparently nobody hit that for years.

Cc: Eric Biggers <ebiggers@kernel.org>
Cc: stable@vger.kernel.org
Fixes: bfd9efddf990 ("crypto: nx - convert AES-ECB to skcipher API")
Fixes: 9420e628e7d8 ("crypto: nx - Use API partial block handling")
Acked-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Reported-by: Calvin Buckley <calvin@cmpct.info>
Tested-by: Calvin Buckley <calvin@cmpct.info>
Suggested-by: Brad Spengler <brad.spengler@opensrcsec.com>
Signed-off-by: Sam James <sam@gentoo.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>