crypto: sparc - replace memset by memzero_explicit

Memset on a local variable may be removed when it is called just before the
variable goes out of scope.  Using memzero_explicit defeats this
optimization.  A simplified version of the semantic patch that makes this
change is as follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
type T;
@@

{
... when any
T x[...];
... when any
    when exists
- memset
+ memzero_explicit
  (x,
-0,
  ...)
... when != x
    when strict
}
// </smpl>

This change was suggested by Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

arch/sparc/crypto/sha256_glue.c

@@ -135,7 +135,7 @@ static int sha224_sparc64_final(struct shash_desc *desc, u8 *hash)
 	sha256_sparc64_final(desc, D);
 
 	memcpy(hash, D, SHA224_DIGEST_SIZE);
-	memset(D, 0, SHA256_DIGEST_SIZE);
+	memzero_explicit(D, SHA256_DIGEST_SIZE);
 
 	return 0;
 }

arch/sparc/crypto/sha512_glue.c

@@ -139,7 +139,7 @@ static int sha384_sparc64_final(struct shash_desc *desc, u8 *hash)
 	sha512_sparc64_final(desc, D);
 
 	memcpy(hash, D, 48);
-	memset(D, 0, 64);
+	memzero_explicit(D, 64);
 
 	return 0;
 }