Add conf parameter to mbedtls_ssl_handshake_free

This function is declared in ssl_internal.h, so this is not a public
API change.

This is in preparation for mbedtls_ssl_handshake_free needing to call
methods from the config structure.
diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 756360b..f990243 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -385,9 +385,11 @@
  * \brief           Free referenced items in an SSL handshake context and clear
  *                  memory
  *
+ * \param conf      SSL configuration
  * \param handshake SSL handshake context
  */
-void mbedtls_ssl_handshake_free( mbedtls_ssl_handshake_params *handshake );
+void mbedtls_ssl_handshake_free( const mbedtls_ssl_config *conf,
+                                 mbedtls_ssl_handshake_params *handshake );
 
 int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl );
 int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl );
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 2690e46..9482723 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5153,7 +5153,7 @@
     /*
      * Free our handshake params
      */
-    mbedtls_ssl_handshake_free( ssl->handshake );
+    mbedtls_ssl_handshake_free( ssl->conf, ssl->handshake );
     mbedtls_free( ssl->handshake );
     ssl->handshake = NULL;
 
@@ -5508,7 +5508,7 @@
     if( ssl->session_negotiate )
         mbedtls_ssl_session_free( ssl->session_negotiate );
     if( ssl->handshake )
-        mbedtls_ssl_handshake_free( ssl->handshake );
+        mbedtls_ssl_handshake_free( ssl->conf, ssl->handshake );
 
     /*
      * Either the pointers are now NULL or cleared properly and can be freed.
@@ -7263,10 +7263,12 @@
 }
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
-void mbedtls_ssl_handshake_free( mbedtls_ssl_handshake_params *handshake )
+void mbedtls_ssl_handshake_free( const mbedtls_ssl_config *conf,
+                                 mbedtls_ssl_handshake_params *handshake )
 {
     if( handshake == NULL )
         return;
+    (void) conf; /*unused in some compile-time configurations*/
 
 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
     defined(MBEDTLS_SSL_PROTO_TLS1_1)
@@ -7397,7 +7399,7 @@
 
     if( ssl->handshake )
     {
-        mbedtls_ssl_handshake_free( ssl->handshake );
+        mbedtls_ssl_handshake_free( ssl->conf, ssl->handshake );
         mbedtls_ssl_transform_free( ssl->transform_negotiate );
         mbedtls_ssl_session_free( ssl->session_negotiate );