crypto: doc - update AEAD AD handling

The associated data handling with the kernel crypto API has been
updated. This needs to be reflected in the documentation.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/crypto/aead.h b/include/crypto/aead.h
index 84d13b1..957bb87 100644
--- a/include/crypto/aead.h
+++ b/include/crypto/aead.h
@@ -31,10 +31,10 @@
  *
  * For example: authenc(hmac(sha256), cbc(aes))
  *
- * The example code provided for the asynchronous block cipher operation
- * applies here as well. Naturally all *ablkcipher* symbols must be exchanged
+ * The example code provided for the symmetric key cipher operation
+ * applies here as well. Naturally all *skcipher* symbols must be exchanged
  * the *aead* pendants discussed in the following. In addition, for the AEAD
- * operation, the aead_request_set_assoc function must be used to set the
+ * operation, the aead_request_set_ad function must be used to set the
  * pointer to the associated data memory location before performing the
  * encryption or decryption operation. In case of an encryption, the associated
  * data memory is filled during the encryption operation. For decryption, the