- minor fix, enclosed macro argument in brackets

src/headers/check_helper.h

@@ -49,7 +49,7 @@ void __clean_render_pipeline( retmsg_t ** pointer );
 
 #define GET_EMPTY_RET(ret) \
   ret_t ret; \
-  ret.value_found = NULL; \
-  ret.logical_or_count = 0; \
-  ret.returncode = should_not_occur;
+  (ret).value_found = NULL; \
+  (ret).logical_or_count = 0; \
+  (ret).returncode = should_not_occur;
 #endif