[CRYPTO] api: fix writting into unallocated memory in setkey_aligned

setkey_unaligned() commited in ca7c39385ce1a7b44894a4b225a4608624e90730
overwrites unallocated memory in the following memset() because
I used the wrong buffer length.

Signed-off-by: Sebastian Siewior <sebastian@breakpoint.cc>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/hash.c b/crypto/hash.c
index 4d75ca7..4fd470b 100644
--- a/crypto/hash.c
+++ b/crypto/hash.c
@@ -40,7 +40,7 @@
 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 	memcpy(alignbuffer, key, keylen);
 	ret = alg->setkey(crt, alignbuffer, keylen);
-	memset(alignbuffer, 0, absize);
+	memset(alignbuffer, 0, keylen);
 	kfree(buffer);
 	return ret;
 }