perf tests attr: Do not store failed events

Do not mess up our temp space with files we don't
need - failed event open attempts.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20170703145030.12903-3-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/attr.c

@@ -136,7 +136,7 @@ void test_attr__open(struct perf_event_attr *attr, pid_t pid, int cpu,
 {
 	int errno_saved = errno;
 
-	if (store_event(attr, pid, cpu, fd, group_fd, flags)) {
+	if ((fd != -1) && store_event(attr, pid, cpu, fd, group_fd, flags)) {
 		pr_err("test attr FAILED");
 		exit(128);
 	}