Fix log location for async logger

Summary: As titled. The log should be in the if-block when log size is larger than current write buffer.

Differential Revision: D85835819

fbshipit-source-id: ba7b40b2cd18839b92a1d94e9de9b93ad553d775

Author: Ron He

fboss/agent/AsyncLoggerBase.cpp

@@ -145,8 +145,8 @@ void AsyncLoggerBase::appendLog(const char* logRecord, size_t logSize) {
 
   // Acquire the lock and check if there's enough space in the buffer
   latch_.lock();
-  // Release the lock and notify worker thread to flush logs
   if (logSize + getOffset() >= bufferSize_) {
+    // Release the lock and notify worker thread to flush logs
     fullFlush_ = true;
     latch_.unlock();
     cv_.notify_one();