cleanup from "tcmur: add passthrough handler support"
cleanup from "tcmur: add passthrough handler support"

commit: tcmur: remove useless 'wakeup' parameter
removed the wakeup variable use, but then commit:
tcmur: add tcmur_cmd_passthrough_handler support
added another instance.

commit: Add tcmu_get_runner_handler helper
added a helper to get the handler from the dev
but then commit: tcmur: add passthrough handler support
added another rhandler access but did not use the
helper.

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