[RF] Fix checking of multi-partition batch computations in RooNLLVar.
[RF] Fix checking of multi-partition batch computations in RooNLLVar.

olifre/root,olifre/root,olifre/root,root-mirror/root,olifre/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,olifre/root