Fix some FX_BOOL / int noise in fxcrt.

core/fxcrt/fxcrt_windows.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fxcrt/fxcrt_windows.h"
 
 #include "core/fxcrt/fx_string.h"
 
@@ skipping 142 matching lines @@
   }
   if (SetPosition(pos) == (FX_FILESIZE)-1) {
     return 0;
   }
   return Write(pBuffer, szBuffer);
 }
 FX_BOOL CFXCRT_FileAccess_Win64::Flush() {
   if (!m_hFile) {
     return FALSE;
   }
-  return ::FlushFileBuffers(m_hFile);
+  return !!::FlushFileBuffers(m_hFile);
 }
 FX_BOOL CFXCRT_FileAccess_Win64::Truncate(FX_FILESIZE szFile) {
   if (SetPosition(szFile) == (FX_FILESIZE)-1) {
     return FALSE;
   }
-  return ::SetEndOfFile(m_hFile);
+  return !!::SetEndOfFile(m_hFile);
 }
 #endif