perf utils: Check verbose flag properly

It now can have negative value to suppress the message entirely.  So it
needs to check it being positive.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170217081742.17417-3-namhyung@kernel.org
[ Adjust fuzz on tools/perf/util/pmu.c, add > 0 checks in many other places ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/dso.c

@@ -1058,7 +1058,7 @@ int dso__name_len(const struct dso *dso)
 {
 	if (!dso)
 		return strlen("[unknown]");
-	if (verbose)
+	if (verbose > 0)
 		return dso->long_name_len;
 
 	return dso->short_name_len;