Fix cpp example for old compillers

Jan Breuer

2016-06-02 4998131d17b97cf0cf7260acfb91d6fcadf522eb

 libscpi/inc/scpi/types.h

@@ -203,7 +203,7 @@

    struct _scpi_error_info_heap_t {
        size_t wr;
        //size_t rd;
        /* size_t rd; */
        size_t count;
        size_t size;
        char * data;