perf test: Suppress libtraceevent warnings

Currently libtraceevent emits warning on unsupported event formats.
However it'd be better to see them only -v option is given.  To do that,
it needs to override the warning() function which is used in the
libtracevent.  Thus add set_warning_routine() same as set_die_routine()
and check the verbose flag in our warning routine.

Before:
  # perf test 5
   5: parse events tests                                       :
    Warning: [kvmmmu:kvm_mmu_get_page] bad op token {
    Warning: [kvmmmu:kvm_mmu_sync_page] bad op token {
    Warning: [kvmmmu:kvm_mmu_unsync_page] bad op token {
    Warning: [kvmmmu:kvm_mmu_prepare_zap_page] bad op token {
    Warning: [kvmmmu:fast_page_fault] function is_writable_pte not defined
    ...
   Ok

After:
  # perf test 5
   5: parse events tests                                       : Ok

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1445268229-1601-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
index 0648b84..636d7b4 100644
--- a/tools/perf/tests/parse-events.c
+++ b/tools/perf/tests/parse-events.c
@@ -5,6 +5,7 @@
 #include <api/fs/fs.h>
 #include "tests.h"
 #include "debug.h"
+#include "util.h"
 #include <linux/hw_breakpoint.h>
 #include <api/fs/fs.h>
 
@@ -1753,6 +1754,17 @@
 	return ret;
 }
 
+static void debug_warn(const char *warn, va_list params)
+{
+	char msg[1024];
+
+	if (!verbose)
+		return;
+
+	vsnprintf(msg, sizeof(msg), warn, params);
+	fprintf(stderr, " Warning: %s\n", msg);
+}
+
 int test__parse_events(void)
 {
 	int ret1, ret2 = 0;
@@ -1764,6 +1776,8 @@
 		ret2 = ret1;				\
 } while (0)
 
+	set_warning_routine(debug_warn);
+
 	TEST_EVENTS(test__events);
 
 	if (test_pmu())