If no cycles event is found by grep don't fail the grep.
Tweak the reg-exp to allow cpu-cycles on ARM.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/tests/shell/stat.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/stat.sh b/tools/perf/tests/shell/stat.sh
index 8a100a7f2dc1..45041827745d 100755
--- a/tools/perf/tests/shell/stat.sh
+++ b/tools/perf/tests/shell/stat.sh
@@ -196,7 +196,7 @@ test_hybrid() {
   fi
 
   # Run default Perf stat
-  cycles_events=$(perf stat -- true 2>&1 | grep -E "/cycles/[uH]*|  cycles[:uH]*  " -c)
+  cycles_events=$(perf stat -- true 2>&1 | grep -E "cycles/[uH]*|  cycles[:uH]*  " -c || true)
 
   # The expectation is that default output will have a cycles events on each
   # hybrid PMU. In situations with no cycles PMU events, like virtualized, this
-- 
2.51.0.384.g4c02a37b29-goog