Replace some stray _T()s with wxT().

We use wxT() exclusively now so replace some _T()s which crept in unnoticed.

This also fixes compilation using Sun CC.

See #12452.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65659 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/fldlgcmn.cpp

@@ -186,7 +186,7 @@ void wxFileDialogBase::SetPath(const wxString& path)
     wxString ext;
     wxFileName::SplitPath(path, &m_dir, &m_fileName, &ext);
     if ( !ext.empty() )
-        m_fileName << _T('.') << ext;
+        m_fileName << wxT('.') << ext;
     m_path = path;
 }