Fix allocateSlice for EB (#3391)

The slice data has a different BoxArray, so we cannot use the original
Factory.

## Checklist

The proposed changes:
- [x] fix a bug or incorrect behavior in AMReX
- [ ] add new capabilities to AMReX
- [ ] changes answers in the test suite to more than roundoff level
- [ ] are likely to significantly affect the results of downstream AMReX
users
- [ ] include documentation in the code and/or rst files, if appropriate

Src/Base/AMReX_MultiFabUtil.cpp

@@ -47,9 +47,9 @@ namespace {
  }
  BoxArray slice_ba(&boxes[0], static_cast<int>(boxes.size()));
  DistributionMapping slice_dmap(std::move(procs));
- std::unique_ptr<MultiFab> slice(new MultiFab(slice_ba, slice_dmap, ncomp, 0,
-  MFInfo(), cell_centered_data.Factory()));
- return slice;
+
+ return std::make_unique<MultiFab>(slice_ba, slice_dmap, ncomp, 0,
+  MFInfo(), FArrayBoxFactory());
  }
 }