ssl_msg.c: fix parm in call to mbedtls_ssl_decrypt_buf()

Signed-off-by: Przemyslaw Stekiel <przemyslaw.stekiel@mobica.com>
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 2353c5e..e473c27 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -1332,7 +1332,7 @@
                                add_data, add_data_len,
                                data, rec->data_len + transform->taglen,
                                data, rec->buf_len - (data - rec->buf),
-                               &rec->data_len );
+                               &olen );
 
         if( status != PSA_SUCCESS )
             return( psa_status_to_mbedtls( status ) );