Remove duplicate mbedtls_platform_zeroize for tls13_early_secrets

Signed-off-by: Yanray Wang <yanray.wang@arm.com>
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index c951a36..10effa2 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -1178,10 +1178,6 @@
     traffic_keys->key_len = key_len;
     traffic_keys->iv_len = iv_len;
 
-    /* Erase early secrets */
-    mbedtls_platform_zeroize(
-        &tls13_early_secrets, sizeof(mbedtls_ssl_tls13_early_secrets));
-
     MBEDTLS_SSL_DEBUG_BUF(4, "client early write_key",
                           traffic_keys->client_write_key,
                           traffic_keys->key_len);