crypto: ccree - remove set but not used variable 'du_size'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/crypto/ccree/cc_cipher.c: In function cc_setup_key_desc:
drivers/crypto/ccree/cc_cipher.c:645:15: warning: variable du_size set but not used [-Wunused-but-set-variable]

It is never used since introduction in
commit dd8486c7 ("crypto: ccree - move key load desc. before flow desc.")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccree/cc_cipher.c

@@ -642,16 +642,8 @@ static void cc_setup_key_desc(struct crypto_tfm *tfm,
 	int direction = req_ctx->gen_ctx.op_type;
 	dma_addr_t key_dma_addr = ctx_p->user.key_dma_addr;
 	unsigned int key_len = ctx_p->keylen;
-	unsigned int du_size = nbytes;
 	unsigned int din_size;
 
-	struct cc_crypto_alg *cc_alg =
-		container_of(tfm->__crt_alg, struct cc_crypto_alg,
-			     skcipher_alg.base);
-
-	if (cc_alg->data_unit)
-		du_size = cc_alg->data_unit;
-
 	switch (cipher_mode) {
 	case DRV_CIPHER_CBC:
 	case DRV_CIPHER_CBC_CTS: