Running shellcheck on stat_bpf_counter.sh generates below
warning:

   In tests/shell/stat_bpf_counters.sh line 34:
   if [ "$base_cycles" == "<not" ]; then
                       ^-- SC3014 (warning): In POSIX sh, == in place of = is undefined.

   In tests/shell/stat_bpf_counters.sh line 39:
   if [ "$bpf_cycles" == "<not" ]; then
                      ^-- SC3014 (warning): In POSIX sh, == in place of = is undefined.

Fix this by using "=" instead of "==" to work for
all shells.

Signed-off-by: Athira Rajeev <redacted>
---
 tools/perf/tests/shell/stat_bpf_counters.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/tests/shell/stat_bpf_counters.sh b/tools/perf/tests/shell/stat_bpf_counters.sh
index 13473aeba489..513cd1e58e0e 100755
--- a/tools/perf/tests/shell/stat_bpf_counters.sh
+++ b/tools/perf/tests/shell/stat_bpf_counters.sh

@@ -31,12 +31,12 @@ if ! perf stat --bpf-counters true > /dev/null 2>&1; then
 fi
 
 base_cycles=$(perf stat --no-big-num -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')
-if [ "$base_cycles" == "<not" ]; then
+if [ "$base_cycles" = "<not" ]; then
 	echo "Skipping: cycles event not counted"
 	exit 2
 fi
 bpf_cycles=$(perf stat --no-big-num --bpf-counters -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')
-if [ "$bpf_cycles" == "<not" ]; then
+if [ "$bpf_cycles" = "<not" ]; then
 	echo "Failed: cycles not counted with --bpf-counters"
 	exit 1
 fi

-- 
2.39.1