runner: fix crash during shutdown
runner: fix crash during shutdown

tcmulib closes devices and shuts everything down including their
cmdproc threads, so remove call to tcmulib_cleanup_all_cmdproc_threads
as this can lead to crashes due to those resources already being
freed when tcmulib_close does the remove_device calls.

Signed-off-by: Mike Christie <39daeb1549a929782e38aa87c4e3da7f3844b09a@redhat.com>

open-iscsi/tcmu-runner,open-iscsi/tcmu-runner,agrover/tcmu-runner