Fix undefined order of evaluation.

Fix undefined order of evaluation.

Within a sequence such as
  deallog << is1.n_elements() << ", " << is1.pop_front() << std::endl;
the order of calls to 'n_elements()' and 'pop_front()' is undefined. Consequently,
there are two possible correct output files.

Fix this by splitting the line into two complete statements, separated by
a semicolon (which implies a sequence point).