Don't call CacheBestSize() from DoGetBestSize() implementations

This is unnecessary, wxWindow::GetBestSize() already does this, so calling it
from DoGetBestSize() called by it too is just useless.

src/msw/commandlinkbutton.cpp

@@ -194,8 +194,6 @@ wxSize wxCommandLinkButton::DoGetBestSize() const
     if ( !GetNote().empty() )
         size.y += MAINLABEL_NOTE_MARGIN;
 
-    CacheBestSize(size);
-
     return size;
 }