analysis.lami: remove unused font height for error labels

analysis.lami: remove unused font height for error labels

The method setHeight() does not modify the reciever. Thus,
the size of the error label didn't change.

Change-Id: I1cb656429d5a45dff310c8f6fe94aa99760b92fa
Signed-off-by: Gabriel-Andrew Pollo-Guilbert <gabrielpolloguilbert@gmail.com>
Reviewed-on: https://git.eclipse.org/r/73981
Reviewed-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Reviewed-by: Hudson CI
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Tested-by: Genevieve Bastien <gbastien+lttng@versatic.net>