starmath: Make some functions private, instead of protected

Change-Id: Ic1192a2fca86833e9efd954c7625fb4f84f46b7c
Reviewed-on: https://gerrit.libreoffice.org/33618Reviewed-by: Takeshi Abe <tabe@fixedpoint.jp>
Tested-by: Takeshi Abe <tabe@fixedpoint.jp>

starmath/inc/rect.hxx

@@ -106,7 +106,6 @@ class SmRect
     bool    bHasBaseline,
             bHasAlignInfo;
 
-protected:
     inline  void CopyMBL(const SmRect& rRect);
             void CopyAlignInfo(const SmRect& rRect);