Reduce usage of operator LPCWSTR from CFX_WideString().

core/src/fxcrt/fx_basic_wstring.cpp

Index: core/src/fxcrt/fx_basic_wstring.cpp
diff --git a/core/src/fxcrt/fx_basic_wstring.cpp b/core/src/fxcrt/fx_basic_wstring.cpp
index dfdbef8bd61ceb5e6293aa2ef06d95e3b0c03313..e255aa0779c3a7f8e10c68e9d9480e13fc68b0fc 100644
--- a/core/src/fxcrt/fx_basic_wstring.cpp
+++ b/core/src/fxcrt/fx_basic_wstring.cpp
@@ -1062,13 +1062,13 @@ static CFX_ByteString _DefMap_GetByteString(CFX_CharMap* pCharMap, const CFX_Wid
 {
     int src_len = widestr.GetLength();
     int codepage = pCharMap->m_GetCodePage ? pCharMap->m_GetCodePage() : 0;
-    int dest_len = FXSYS_WideCharToMultiByte(codepage, 0, widestr, src_len, NULL, 0, NULL, NULL);
+    int dest_len = FXSYS_WideCharToMultiByte(codepage, 0, widestr.c_str(), src_len, NULL, 0, NULL, NULL);
     if (dest_len == 0) {
         return CFX_ByteString();
     }
     CFX_ByteString bytestr;
     FX_LPSTR dest_buf = bytestr.GetBuffer(dest_len);
-    FXSYS_WideCharToMultiByte(codepage, 0, widestr, src_len, dest_buf, dest_len, NULL, NULL);
+    FXSYS_WideCharToMultiByte(codepage, 0, widestr.c_str(), src_len, dest_buf, dest_len, NULL, NULL);
     bytestr.ReleaseBuffer(dest_len);
     return bytestr;
 }