perf tests: Fix 'Roundtrip evsel->name' on core-only system

If the atom CPUs are offlined, the 'cpu_atom' is not valid.
Perf will not create two events for one hw event, so the
evsel->idx doesn't need to be divided by 2 before comparing.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210708013701.20347-4-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/evsel-roundtrip-name.c

@@ -5,6 +5,7 @@
 #include "tests.h"
 #include "debug.h"
 #include "pmu.h"
+#include "pmu-hybrid.h"
 #include <errno.h>
 #include <linux/kernel.h>
 
@@ -102,7 +103,7 @@ int test__perf_evsel__roundtrip_name_test(struct test *test __maybe_unused, int
 {
 	int err = 0, ret = 0;
 
-	if (perf_pmu__has_hybrid())
+	if (perf_pmu__has_hybrid() && perf_pmu__hybrid_mounted("cpu_atom"))
 		return perf_evsel__name_array_test(evsel__hw_names, 2);
 
 	err = perf_evsel__name_array_test(evsel__hw_names, 1);