Rename hs->public_key.

This is an unhelpfully generic name. Rename it to match SSL_ECDH_CTX.
Unqualified "public key" is typically assumed to be the certificate.

Change-Id: I8ba8c3f2bb1343d1c006845a1110e833451c5a56
Reviewed-on: https://boringssl-review.googlesource.com/14564
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 793e2d7..2acd422 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -2336,7 +2336,8 @@
       !SSL_ECDH_CTX_init(&group, group_id) ||
       !SSL_ECDH_CTX_accept(&group, &public_key, &secret, &secret_len, out_alert,
                            CBS_data(&peer_key), CBS_len(&peer_key)) ||
-      !CBB_finish(&public_key, &hs->public_key, &hs->public_key_len)) {
+      !CBB_finish(&public_key, &hs->ecdh_public_key,
+                  &hs->ecdh_public_key_len)) {
     OPENSSL_free(secret);
     SSL_ECDH_CTX_cleanup(&group);
     CBB_cleanup(&public_key);
@@ -2360,14 +2361,15 @@
       !CBB_add_u16_length_prefixed(out, &kse_bytes) ||
       !CBB_add_u16(&kse_bytes, group_id) ||
       !CBB_add_u16_length_prefixed(&kse_bytes, &public_key) ||
-      !CBB_add_bytes(&public_key, hs->public_key, hs->public_key_len) ||
+      !CBB_add_bytes(&public_key, hs->ecdh_public_key,
+                     hs->ecdh_public_key_len) ||
       !CBB_flush(out)) {
     return 0;
   }
 
-  OPENSSL_free(hs->public_key);
-  hs->public_key = NULL;
-  hs->public_key_len = 0;
+  OPENSSL_free(hs->ecdh_public_key);
+  hs->ecdh_public_key = NULL;
+  hs->ecdh_public_key_len = 0;
 
   hs->new_session->group_id = group_id;
   return 1;