crypto: LLVMLinux: Remove VLAIS from crypto/omap_sham.c

Replaced the use of a Variable Length Array In Struct (VLAIS) with a C99
compliant equivalent. This patch allocates the appropriate amount of memory
using a char array using the SHASH_DESC_ON_STACK macro.

The new code can be compiled with both gcc and clang.
Signed-off-by: Behan Webster <behanw@converseincode.com>
Reviewed-by: Mark Charlebois <charlebm@gmail.com>
Reviewed-by: Jan-Simon Möller <dl9pf@gmx.de>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-sham.c

@@ -949,17 +949,14 @@ static int omap_sham_finish_hmac(struct ahash_request *req)
 	struct omap_sham_hmac_ctx *bctx = tctx->base;
 	int bs = crypto_shash_blocksize(bctx->shash);
 	int ds = crypto_shash_digestsize(bctx->shash);
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(bctx->shash)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, bctx->shash);
 
-	desc.shash.tfm = bctx->shash;
-	desc.shash.flags = 0; /* not CRYPTO_TFM_REQ_MAY_SLEEP */
+	shash->tfm = bctx->shash;
+	shash->flags = 0; /* not CRYPTO_TFM_REQ_MAY_SLEEP */
 
-	return crypto_shash_init(&desc.shash) ?:
-	       crypto_shash_update(&desc.shash, bctx->opad, bs) ?:
-	       crypto_shash_finup(&desc.shash, req->result, ds, req->result);
+	return crypto_shash_init(shash) ?:
+	       crypto_shash_update(shash, bctx->opad, bs) ?:
+	       crypto_shash_finup(shash, req->result, ds, req->result);
 }
 
 static int omap_sham_finish(struct ahash_request *req)
@@ -1118,18 +1115,15 @@ static int omap_sham_update(struct ahash_request *req)
 	return omap_sham_enqueue(req, OP_UPDATE);
 }
 
-static int omap_sham_shash_digest(struct crypto_shash *shash, u32 flags,
+static int omap_sham_shash_digest(struct crypto_shash *tfm, u32 flags,
 				  const u8 *data, unsigned int len, u8 *out)
 {
-	struct {
-		struct shash_desc shash;
-		char ctx[crypto_shash_descsize(shash)];
-	} desc;
+	SHASH_DESC_ON_STACK(shash, tfm);
 
-	desc.shash.tfm = shash;
-	desc.shash.flags = flags & CRYPTO_TFM_REQ_MAY_SLEEP;
+	shash->tfm = tfm;
+	shash->flags = flags & CRYPTO_TFM_REQ_MAY_SLEEP;
 
-	return crypto_shash_digest(&desc.shash, data, len, out);
+	return crypto_shash_digest(shash, data, len, out);
 }
 
 static int omap_sham_final_shash(struct ahash_request *req)