Get rid of FX_LPCSTR cast.

core/src/fxcrt/fxcrt_platforms.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 "../../include/fxcrt/fx_ext.h"
 #include "fxcrt_platforms.h"
 #if (_FXM_PLATFORM_ != _FXM_PLATFORM_WINDOWS_ && _FXM_PLATFORM_ != _FXM_PLATFORM_LINUX_ && _FXM_PLATFORM_ != _FXM_PLATFORM_APPLE_ && _FXM_PLATFORM_ != _FXM_PLATFORM_ANDROID_)
 IFXCRT_FileAccess* FXCRT_FileAccess_Create()
@@ skipping 28 matching lines @@
 {
     Close();
 }
 FX_BOOL CFXCRT_FileAccess_CRT::Open(FX_BSTR fileName, FX_DWORD dwMode)
 {
     if (m_hFile) {
         return FALSE;
     }
     CFX_ByteString strMode;
     FXCRT_GetFileModeString(dwMode, strMode);
-    m_hFile = FXSYS_fopen(fileName.GetCStr(), (FX_LPCSTR)strMode);
+    m_hFile = FXSYS_fopen(fileName.GetCStr(), strMode.c_str());
     return m_hFile != NULL;
 }
 FX_BOOL CFXCRT_FileAccess_CRT::Open(FX_WSTR fileName, FX_DWORD dwMode)
 {
     if (m_hFile) {
         return FALSE;
     }
     CFX_WideString strMode;
     FXCRT_GetFileModeString(dwMode, strMode);
     m_hFile = FXSYS_wfopen(fileName.GetPtr(), strMode.c_str());
@@ skipping 126 matching lines @@
 }
 FX_BOOL FX_File_Move(FX_BSTR fileNameSrc, FX_BSTR fileNameDst)
 {
     return rename(fileNameSrc.GetCStr(), fileNameDst.GetCStr());
 }
 FX_BOOL FX_File_Move(FX_WSTR fileNameSrc, FX_WSTR fileNameDst)
 {
     return FX_File_Move(FX_UTF8Encode(fileNameSrc), FX_UTF8Encode(fileNameDst));
 }
 #endif