Use the proper macro to convert a bool to a Datum.
The original coding was
var->value = (Datum) state;
which is bogus, and then in commit
2f0f7b4bce13e68394543728801ef011fd82fac6
it was "corrected" to
var->value = PointerGetDatum(state);
which is a faithful translation but still wrong.
This seems purely cosmetic, though, so no need for a back-patch.
Pavel Stehule