crypto: qce - use __free() for a buffer that's always freed

The buffer allocated in qce_ahash_hmac_setkey is always freed before
returning to use __free() to automate it.

Signed-off-by: Bartosz Golaszewski <[e-mail]>
Reviewed-by: Neil Armstrong <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/qce/sha.c

···
  * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
 #include <linux/interrupt.h>
···
 	struct scatterlist sg;
 	unsigned int blocksize;
 	struct crypto_ahash *ahash_tfm;
-	u8 *buf;
 	int ret;
 	const char *alg_name;
 
···
 				   crypto_req_done, &wait);
 	crypto_ahash_clear_flags(ahash_tfm, ~0);
 
-	buf = kzalloc(keylen + QCE_MAX_ALIGN_SIZE, GFP_KERNEL);
+	u8 *buf __free(kfree) = kzalloc(keylen + QCE_MAX_ALIGN_SIZE,
+					GFP_KERNEL);
 	if (!buf) {
 		ret = -ENOMEM;
 		goto err_free_req;
···
 
 	ret = crypto_wait_req(crypto_ahash_digest(req), &wait);
 
-	kfree(buf);
 err_free_req:
 	ahash_request_free(req);
 err_free_ahash: