lttng: add names of traces in sync algorithm stats

lttng: add names of traces in sync algorithm stats

Two lines were added to match traces Ids with traces names so it can be
easier to see which pairs were synchronized.

Change-Id: Iec69283080a12668c02d5886b4bbf95e1440ac00
Signed-off-by: Cédric Biancheri <cdc.biancheri@gmail.com>
Reviewed-on: https://git.eclipse.org/r/74674
Reviewed-by: Hudson CI
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Tested-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>