xml.ui: Fix pattern statistics viewer not refreshing data

xml.ui: Fix pattern statistics viewer not refreshing data

The pattern statistics view was not refreshing the data when switching
the view for an other analysis of the same trace.

Change-Id: I9d2532da971e9fd1013401d481c190df886f45e8
Signed-off-by: Jean-Christian Kouame <jean-christian.kouame@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/97228
Reviewed-by: Hudson CI
Reviewed-by: Genevieve Bastien <gbastien+lttng@versatic.net>
Tested-by: Genevieve Bastien <gbastien+lttng@versatic.net>