crypto: remove several VLAs

We avoid various VLAs[1] by using constant expressions for block size
and alignment mask.

[1] http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/cipher.c b/crypto/cipher.c
index 94fa355..57836c3 100644
--- a/crypto/cipher.c
+++ b/crypto/cipher.c
@@ -13,6 +13,7 @@
  *
  */
 
+#include <crypto/algapi.h>
 #include <linux/kernel.h>
 #include <linux/crypto.h>
 #include <linux/errno.h>
@@ -67,7 +68,7 @@
 {
 	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
 	unsigned int size = crypto_tfm_alg_blocksize(tfm);
-	u8 buffer[size + alignmask];
+	u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
 	u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 
 	memcpy(tmp, src, size);