shellcheck: test_workqueue_*.sh issue
In test_workqueue_efd.sh line 3:
${builddir:-.}/src/test/test_workqueue \
^-- SC2086: Double quote to prevent globbing and word splitting.
Also applies to test_workqueue_efd2.sh, test_workqueue_pipe.sh, test_workqueue_pipe2.sh and test_workqueue_socketpair.sh.