Fixed a bug in clearing the queue accumulated during USR1 processing

src/sighandlers.cpp

@@ -113,9 +113,7 @@ void S3fsSignals::CheckCacheWorker(Semaphore* pSem)
         }
 
         // do not allow request queuing
-        for(int value = pSem->get_value(); 0 < value; value = pSem->get_value()){
-            pSem->wait();
-        }
+        while(pSem->try_wait());
     }
 }