Don't reference malloc if not using alloc/free

Rich Barlow

2017-01-30 219ca4fc80ef6491555b403c6884566c8e1deefd

 libscpi/inc/scpi/constants.h

@@ -51,7 +51,7 @@
/* 21.8 :ERRor Subsystem
 * The maximum string length of <Error/event_description> plus <Device-dependent_info> is 255 characters.
 */
#define SCPI_STD_ERROR_DESC_CHARS_LIMIT 255
#define SCPI_STD_ERROR_DESC_MAX_STRING_LENGTH 255

#ifdef   __cplusplus
}