Revert "crypto: ahash - Set default reqsize from ahash_alg"

This reverts commit 3a0c8429ab which is
commit 9e01aaa1033d6e40f8d7cf4f20931a61ce9e3f04 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I29c21260e15c6e3982fe7eccd38330f470fa0167
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

crypto/ahash.c

@@ -427,7 +427,6 @@ static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
 	hash->setkey = ahash_nosetkey;
 
 	crypto_ahash_set_statesize(hash, alg->halg.statesize);
-	crypto_ahash_set_reqsize(hash, alg->reqsize);
 
 	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
 		return crypto_init_shash_ops_async(tfm);
@@ -600,9 +599,6 @@ static int ahash_prepare_alg(struct ahash_alg *alg)
 	if (alg->halg.statesize == 0)
 		return -EINVAL;
 
-	if (alg->reqsize && alg->reqsize < alg->halg.statesize)
-		return -EINVAL;
-
 	err = hash_prepare_alg(&alg->halg);
 	if (err)
 		return err;

include/crypto/hash.h

@@ -154,7 +154,6 @@ struct ahash_request {
  *	      This is a counterpart to @init_tfm, used to remove
  *	      various changes set in @init_tfm.
  * @clone_tfm: Copy transform into new object, may allocate memory.
- * @reqsize: Size of the request context.
  * @halg: see struct hash_alg_common
  */
 struct ahash_alg {
@@ -171,8 +170,6 @@ struct ahash_alg {
 	void (*exit_tfm)(struct crypto_ahash *tfm);
 	int (*clone_tfm)(struct crypto_ahash *dst, struct crypto_ahash *src);
 
-	unsigned int reqsize;
-
 	struct hash_alg_common halg;
 };