Fix typo in AES-GCM-SIV comments.

Change-Id: I73bd495cf99bbc8a993a726b009d68e74c893420
Reviewed-on: https://boringssl-review.googlesource.com/c/33684
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/cipher_extra/e_aesgcmsiv.c b/crypto/cipher_extra/e_aesgcmsiv.c
index 1deb918..e3534bb 100644
--- a/crypto/cipher_extra/e_aesgcmsiv.c
+++ b/crypto/cipher_extra/e_aesgcmsiv.c
@@ -60,10 +60,10 @@
 extern void aes128gcmsiv_aes_ks(
     const uint8_t key[16], uint8_t out_expanded_key[16*15]);
 
-// aes128gcmsiv_aes_ks writes an AES-128 key schedule for |key| to
+// aes256gcmsiv_aes_ks writes an AES-256 key schedule for |key| to
 // |out_expanded_key|.
 extern void aes256gcmsiv_aes_ks(
-    const uint8_t key[16], uint8_t out_expanded_key[16*15]);
+    const uint8_t key[32], uint8_t out_expanded_key[16*15]);
 
 static int aead_aes_gcm_siv_asm_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
                                      size_t key_len, size_t tag_len) {