perf test: Remove bash construct from stat_bpf_counters.sh test

Currently the test skips with an error because == only works in bash:

  $ ./perf test 91 -v
  Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
  91: perf stat --bpf-counters test                                   :
  --- start ---
  test child forked, pid 44586
  ./tests/shell/stat_bpf_counters.sh: 26: [: -v: unexpected operator
  test child finished with -2
  ---- end ----
  perf stat --bpf-counters test: Skip

Changing == to = does the same thing, but doesn't result in an error:

  ./perf test 91 -v
  Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
  91: perf stat --bpf-counters test                                   :
  --- start ---
  test child forked, pid 45833
  Skipping: --bpf-counters not supported
    Error: unknown option `bpf-counters'
  [...]
  test child finished with -2
  ---- end ----
  perf stat --bpf-counters test: Skip

Signed-off-by: James Clark <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Florian Fainelli <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: KP Singh <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Martin KaFai Lau <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Sumanth Korikkar <[email protected]>
Cc: Thomas Richter <[email protected]>
Cc: Yonghong Song <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: James-A-Clark

tools/perf/tests/shell/stat_bpf_counters.sh

@@ -23,7 +23,7 @@ compare_number()
 
 # skip if --bpf-counters is not supported
 if ! perf stat --bpf-counters true > /dev/null 2>&1; then
-	if [ "$1" == "-v" ]; then
+	if [ "$1" = "-v" ]; then
 		echo "Skipping: --bpf-counters not supported"
 		perf --no-pager stat --bpf-counters true || true
 	fi