Resolve unused argument warning in SCPI_ErrorAddInternal

info_len may be unused if USE_DEVICE_DEPENDENT_ERROR_INFORMATION is 0

Author: MegabytePhreak

libscpi/src/error.c

@@ -130,6 +130,9 @@ int32_t SCPI_ErrorCount(scpi_t * context) {
 
 static scpi_bool_t SCPI_ErrorAddInternal(scpi_t * context, int16_t err, char * info, size_t info_len) {
     scpi_error_t error_value;
+    /* SCPIDEFINE_strndup is sometimes a dumy that does not reference it's arguments. 
+       Since info_len is not referenced elsewhere caoing to void prevents unusd argument warnings */
+    (void) info_len;
     char * info_ptr = info ? SCPIDEFINE_strndup(&context->error_info_heap, info, info_len) : NULL;
     SCPI_ERROR_SETVAL(&error_value, err, info_ptr);
     if (!fifo_add(&context->error_queue, &error_value)) {