core/cgroup: constify CGROUP_TASKS_MAX_UNSET

src/core/cgroup.h

@@ -14,7 +14,7 @@ typedef struct CGroupTasksMax {
         uint64_t scale;
 } CGroupTasksMax;
 
-#define CGROUP_TASKS_MAX_UNSET ((CGroupTasksMax) { .value = UINT64_MAX, .scale = 0 })
+#define CGROUP_TASKS_MAX_UNSET ((const CGroupTasksMax) { .value = UINT64_MAX, .scale = 0 })
 
 static inline bool cgroup_tasks_max_isset(const CGroupTasksMax *tasks_max) {
         return tasks_max->value != UINT64_MAX || tasks_max->scale != 0;