tools lib traceevent: Unregister handler when jbd2 plugin is is unloaded

The function handlers should be unregistered when the plugin unloaded
otherwise they'll try to access invalid memory.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1389839478-5887-11-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/plugin_jbd2.c

@@ -66,3 +66,12 @@ int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
 				       PEVENT_FUNC_ARG_VOID);
 	return 0;
 }
+
+void PEVENT_PLUGIN_UNLOADER(struct pevent *pevent)
+{
+	pevent_unregister_print_function(pevent, process_jbd2_dev_to_name,
+					 "jbd2_dev_to_name");
+
+	pevent_unregister_print_function(pevent, process_jiffies_to_msecs,
+					 "jiffies_to_msecs");
+}