tmf.core: Move the analysis cancel log message

tmf.core: Move the analysis cancel log message

The analysis cancellation should be logged only if it was running
and is really cancelled. Otherwise, it produces confusing messages
where the analysis was previously finished and then cancelled.

Change-Id: I1704f2a29312b6c1a2a9b15e4869bcb646ab1204
Signed-off-by: Geneviève Bastien <gbastien+lttng@versatic.net>
Reviewed-on: https://git.eclipse.org/r/90577
Reviewed-by: Hudson CI
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Tested-by: Matthew Khouzam <matthew.khouzam@ericsson.com>