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

Commit ce8fd0500b74 ("crypto: qce - use __free() for a buffer that's
always freed") introduced a buggy use of __free(), which clang
rightfully points out:

drivers/crypto/qce/sha.c:365:3: error: cannot jump from this goto statement to its label
365 | goto err_free_ahash;
| ^
drivers/crypto/qce/sha.c:373:6: note: jump bypasses initialization of variable with __attribute__((cleanup))
373 | u8 *buf __free(kfree) = kzalloc(keylen + QCE_MAX_ALIGN_SIZE,
| ^

Jumping over a variable declared with the cleanup attribute does not
prevent the cleanup function from running; instead, the cleanup function
is called with an uninitialized value.

Moving the declaration back to the top function with __free() and a NULL
initialization would resolve the bug but that is really not much
different from the original code. Since the function is so simple and
there is no functional reason to use __free() here, just revert the
original change to resolve the issue.

Fixes: ce8fd0500b74 ("crypto: qce - use __free() for a buffer that's always freed")
Reported-by: Linux Kernel Functional Testing <[e-mail]>
Closes: https://lore.kernel.org/CA+G9fYtpAwXa5mUQ5O7vDLK2xN4t-kJoxgUe1ZFRT=[e-mail]/
Signed-off-by: Nathan Chancellor <[e-mail]>
Acked-by: Bartosz Golaszewski <[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);
 
-	u8 *buf __free(kfree) = kzalloc(keylen + QCE_MAX_ALIGN_SIZE,
-					GFP_KERNEL);
+	buf = 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: