perf evsel: Avoid close(-1)

In some weak fallback cases close can be called a lot with -1. Check for
this case and avoid calling close then.

This is mainly to shut up valgrind which complains about this case.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20191020175202.32456-3-andi@firstfloor.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/evsel.c

@@ -120,6 +120,7 @@ void perf_evsel__close_fd(struct perf_evsel *evsel)
 
 	for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++)
 		for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
+			if (FD(evsel, cpu, thread) >= 0)
 				close(FD(evsel, cpu, thread));
 			FD(evsel, cpu, thread) = -1;
 		}

tools/perf/util/evsel.c

@@ -1815,6 +1815,7 @@ int evsel__open(struct evsel *evsel, struct perf_cpu_map *cpus,
 	old_errno = errno;
 	do {
 		while (--thread >= 0) {
+			if (FD(evsel, cpu, thread) >= 0)
 				close(FD(evsel, cpu, thread));
 			FD(evsel, cpu, thread) = -1;
 		}