[Bug libstdc++/115119] Typo in _Grapheme_cluster_view::_Iterator::operator++(int)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115119

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
No ++this is correct. We want to increment the iterator and not the what the
iterator points too here.