crypto: skcipher - Remove SKCIPHER_REQUEST_ON_STACK()

Now that all the users of the VLA-generating SKCIPHER_REQUEST_ON_STACK()
macro have been moved to SYNC_SKCIPHER_REQUEST_ON_STACK(), we can remove
the former.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/skcipher.h

@@ -156,11 +156,6 @@ struct skcipher_alg {
 			    ] CRYPTO_MINALIGN_ATTR; \
 	struct skcipher_request *name = (void *)__##name##_desc
 
-#define SKCIPHER_REQUEST_ON_STACK(name, tfm) \
-	char __##name##_desc[sizeof(struct skcipher_request) + \
-		crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \
-	struct skcipher_request *name = (void *)__##name##_desc
-
 /**
  * DOC: Symmetric Key Cipher API
  *