perf tools: Add a user event for AUX area tracing errors

Errors encountered when decoding an AUX area trace need to be reported
to the user. However the "user" might be a script or another tool, so
provide a new user event to capture those errors.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1428594864-29309-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
index 0146f8e..20afe19 100644
--- a/tools/perf/util/tool.h
+++ b/tools/perf/util/tool.h
@@ -50,7 +50,8 @@
 	event_oe	finished_round;
 	event_op2	build_id,
 			id_index,
-			auxtrace_info;
+			auxtrace_info,
+			auxtrace_error;
 	event_op3	auxtrace;
 	bool		ordered_events;
 	bool		ordering_requires_timestamps;