clang-format: update c/cc coding style

Update all cc code using .clang-format; please do so as well for future PRs
etc.; emacs has a handy 'clang-format' mode to make this automatic.

For comparing old changes with git blame, we can disregard this one using
--ignore-rev

(see https://www.moxio.com/blog/43/ignoring-bulk-change-commits-with-git-blame )

lib/mu-query-threads.hh

@@ -34,7 +34,7 @@ namespace Mu {
  * @param qres query results
  * @param descending whether to sort the top-level in descending order
  */
-void calculate_threads (QueryResults& qres, bool descending);
+void calculate_threads(QueryResults& qres, bool descending);
 
 } // namespace Mu