Fix: src.ctf.lttng-live: possible memory leak on error path

Fix: src.ctf.lttng-live: possible memory leak on error path

Free `struct lttng_live_component` if the graph is found to be already
canceled and return the appropriate _END status.

Reported-by: scan-build - Potential leak of memory.
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: I975e458ed4ce5dc3e50c9bf330a2f6953e5be535
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1308
Tested-by: jenkins
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>