refactor: use canonical util.nop everywhere.
refactor: use canonical util.nop everywhere.

* specl/specl.lua (nop): Remove.
(compile_example): Use util.nop.

Signed-off-by: Gary V. Vaughan <f9023000f29773649f3850298becb9544b5fd6a9@gnu.org>

gvvaughan/specl