Cleanup: src.ctf.lttng-live: remove usage of `bt_object`

Cleanup: src.ctf.lttng-live: remove usage of `bt_object`

The live_viewer_connection objects are never shared and we can know that
by seeing that there is no to _get_ref() in this entire component class.

This commit also removes the need for the BT_OBJECT_DONT_LOG macro added
by:
    commit 9358ceb38baa2d50a69d7ee580463a2ddba25465
    Author: Philippe Proulx <eeppeliteloop@gmail.com>
    lib/object.h: log conditionally to `BT_OBJECT_DONT_LOG` undefined

so remove that to.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: I2b4ba20613e77048044507a93241bf7db3f58fa2
Reviewed-on: https://review.lttng.org/c/babeltrace/+/2312
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>