Clarifying comment

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/library/cipher.c b/library/cipher.c
index 119e796..ee365a1 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -1471,7 +1471,7 @@
 
 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
 /*
- * Packet-oriented encryption for AEAD modes: public function.
+ * Packet-oriented encryption for AEAD modes: public legacy function.
  */
 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
                          const unsigned char *iv, size_t iv_len,
@@ -1494,7 +1494,7 @@
 }
 
 /*
- * Packet-oriented decryption for AEAD modes: public function.
+ * Packet-oriented decryption for AEAD modes: public legacy function.
  */
 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
                          const unsigned char *iv, size_t iv_len,