Rename Channel ID's EncryptedExtensions to just ChannelID in C.

To match the Go side. That message will never be used for anything else,
so there's not much need to give it such a long name.

Change-Id: I3396c9d513d02d873e59cd8e81ee64005c5c706c
Reviewed-on: https://boringssl-review.googlesource.com/8620
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/ssl/handshake_client.c b/ssl/handshake_client.c
index e3cd102..2ac7dee 100644
--- a/ssl/handshake_client.c
+++ b/ssl/handshake_client.c
@@ -1987,8 +1987,7 @@
   }
 
   CBB cbb, body, child;
-  if (!ssl->method->init_message(ssl, &cbb, &body,
-                                 SSL3_MT_CHANNEL_ID_ENCRYPTED_EXTENSIONS) ||
+  if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_CHANNEL_ID) ||
       !CBB_add_u16(&body, TLSEXT_TYPE_channel_id) ||
       !CBB_add_u16_length_prefixed(&body, &child) ||
       !BN_bn2cbb_padded(&child, 32, x) || !BN_bn2cbb_padded(&child, 32, y) ||