Remove implicit cast from CFX_WideString to (const wchar_t*)

xfa/fxfa/parser/xfa_basic_imp.cpp

Index: xfa/fxfa/parser/xfa_basic_imp.cpp
diff --git a/xfa/fxfa/parser/xfa_basic_imp.cpp b/xfa/fxfa/parser/xfa_basic_imp.cpp
index 07f1b823013c03e41aa131a68de2199a0b384593..112e247016ced324c19a49621f0d7e373027ea79 100644
--- a/xfa/fxfa/parser/xfa_basic_imp.cpp
+++ b/xfa/fxfa/parser/xfa_basic_imp.cpp
@@ -599,7 +599,7 @@ int32_t CXFA_WideTextRead::ReadString(FX_WCHAR* pStr,
   if (iMaxLength > m_wsBuffer.GetLength() - m_iPosition) {
     iMaxLength = m_wsBuffer.GetLength() - m_iPosition;
   }
-  FXSYS_wcsncpy(pStr, (const FX_WCHAR*)m_wsBuffer + m_iPosition, iMaxLength);
+  FXSYS_wcsncpy(pStr, m_wsBuffer.c_str() + m_iPosition, iMaxLength);
   m_iPosition += iMaxLength;
   bEOS = IsEOF();
   return iMaxLength;