[RF] Fix documentation of `RooAbsReal::getValues`
[RF] Fix documentation of `RooAbsReal::getValues`

Closes #9523.

olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root,olifre/root