Move TB state to ssl->s3.

These are connection state, so they should be reset on SSL_clear.

Change-Id: I861fe52578836615d2719c9e1ff0911c798f336e
Reviewed-on: https://boringssl-review.googlesource.com/27384
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>

ssl/ssl_lib.cc

diff --git a/ssl/ssl_lib.cc b/ssl/ssl_lib.cc
index 6312504..14fb0ff 100644
--- a/ssl/ssl_lib.cc
+++ b/ssl/ssl_lib.cc
@@ -2164,11 +2164,11 @@
 }
 
 int SSL_is_token_binding_negotiated(const SSL *ssl) {
-  return ssl->token_binding_negotiated;
+  return ssl->s3->token_binding_negotiated;
 }
 
 uint8_t SSL_get_negotiated_token_binding_param(const SSL *ssl) {
-  return ssl->negotiated_token_binding_param;
+  return ssl->s3->negotiated_token_binding_param;
 }
 
 size_t SSL_get0_certificate_types(SSL *ssl, const uint8_t **out_types) {