fix coding style issue

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 49256ec..d15296f 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -1063,7 +1063,7 @@
     if( ssl->conf->endpoint == MBEDTLS_SSL_IS_CLIENT )
     {
         mbedtls_platform_zeroize( &ssl->handshake->tls13_hs_secrets,
-                                  sizeof(ssl->handshake->tls13_hs_secrets));
+                                  sizeof( ssl->handshake->tls13_hs_secrets ) );
     }
     if( ret != 0 )
     {