Remove redundant Free() from wxFont::SetFractionalPointSize()

Free() is already called from wxFontRefData::SetFractionalPointSize(),
so there is no need to call it from wxFont too and doing this makes this
method gratuitously inconsistent with all the other setters.

No real changes.

src/msw/font.cpp

@@ -855,7 +855,6 @@ void wxFont::SetFractionalPointSize(float pointSize)
 {
     AllocExclusive();
 
-    M_FONTDATA->Free();
     M_FONTDATA->SetFractionalPointSize(pointSize);
 }