perf test: Add verbose skip output for bpf counters

Provide additional context for when the stat bpf counters test skips.
Signed-off-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210617184216.2075588-3-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/stat_bpf_counters.sh

@@ -22,7 +22,13 @@ compare_number()
 }
 
 # skip if --bpf-counters is not supported
-perf stat --bpf-counters true > /dev/null 2>&1 || exit 2
+if ! perf stat --bpf-counters true > /dev/null 2>&1; then
+	if [ "$1" == "-v" ]; then
+		echo "Skipping: --bpf-counters not supported"
+		perf --no-pager stat --bpf-counters true || true
+	fi
+	exit 2
+fi
 
 base_cycles=$(perf stat --no-big-num -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')
 bpf_cycles=$(perf stat --no-big-num --bpf-counters -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')