call static function directly

Summary: This code looks really weird and is otherwise confusing.

Reviewed By: andriigrynenko

Differential Revision: D4730812

fbshipit-source-id: d9f4e73145e81f085ce959a76cdb568d3ae4eb52

folly/futures/ManualExecutor.h

@@ -138,7 +138,7 @@ namespace folly {
       }
     };
     std::priority_queue<ScheduledFunc> scheduledFuncs_;
-    TimePoint now_ = now_.min();
+    TimePoint now_ = TimePoint::min();
   };
 
 }