cli: remove babeltrace2-log

cli: remove babeltrace2-log

babeltrace-log (now renamed to babeltrace2-log) is a legacy tool
provided by Babeltrace 1 used to transform `dmesg` output to CTF.  The
version currently provided by Babeltrace 2 simply runs babeltrace2 with
a pre-defined graph topology.  It does nothing that a user couldn't do
on the command line.

The equivalent now would be:

    dmesg | babeltrace2 -c src.text.dmesg -o ctf -w /path/to/trace

It was therefore decided that it was no longer necessary to provide that
utility, and to remove it.

Change-Id: Id547bced56a8b9913cb152e1309919a15b6fbdd0
Signed-off-by: Simon Marchi <simon.marchi@efficios.com>
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1796
Tested-by: jenkins <jenkins@lttng.org>
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>