Change code base on comments

Change functions name
Change some comments
Improve hrr test case for gnutls

Signed-off-by: XiaokangQian <xiaokang.qian@arm.com>
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 88e7de9..b4af2e0 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -1058,7 +1058,7 @@
  */
 #if defined(MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE)
 
-static int ssl_write_change_cipher_spec_postprocess( mbedtls_ssl_context* ssl )
+static int ssl_tls13_finalize_change_cipher_spec( mbedtls_ssl_context* ssl )
 {
 
 #if defined(MBEDTLS_SSL_CLI_C)
@@ -1115,7 +1115,7 @@
     ssl->out_msgtype = MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC;
 
     /* Update state */
-    MBEDTLS_SSL_PROC_CHK( ssl_write_change_cipher_spec_postprocess( ssl ) );
+    MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_change_cipher_spec( ssl ) );
 
     /* Dispatch message */
     MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_write_record( ssl, 1 ) );