ssl_tls: add missing return brackets 

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index cbb3c62..86fc260 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -559,7 +559,7 @@
     if( status != PSA_SUCCESS )
         return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
 
-    return 0;
+    return( 0 );
 }
 
 #else /* MBEDTLS_USE_PSA_CRYPTO */