perf evsel: Free evsel->filter on the destructor

Noticed with:

  make EXTRA_CFLAGS="-fsanitize=address" BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools-next -C tools/perf install-bin

Direct leak of 45 byte(s) in 1 object(s) allocated from:
    #0 0x7f213f87243b in strdup (/lib64/libasan.so.8+0x7243b)
    #1 0x63d15f in evsel__set_filter util/evsel.c:1371
    #2 0x63d15f in evsel__append_filter util/evsel.c:1387
    #3 0x63d15f in evsel__append_tp_filter util/evsel.c:1400
    #4 0x62cd52 in evlist__append_tp_filter util/evlist.c:1145
    #5 0x62cd52 in evlist__append_tp_filter_pids util/evlist.c:1196
    #6 0x541e49 in trace__set_filter_loop_pids /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3646
    #7 0x541e49 in trace__set_filter_pids /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3670
    #8 0x541e49 in trace__run /home/acme/git/perf-tools/tools/perf/builtin-trace.c:3970
    #9 0x541e49 in cmd_trace /home/acme/git/perf-tools/tools/perf/builtin-trace.c:5141
    #10 0x5ef1a2 in run_builtin /home/acme/git/perf-tools/tools/perf/perf.c:323
    #11 0x4196da in handle_internal_command /home/acme/git/perf-tools/tools/perf/perf.c:377
    #12 0x4196da in run_argv /home/acme/git/perf-tools/tools/perf/perf.c:421
    #13 0x4196da in main /home/acme/git/perf-tools/tools/perf/perf.c:537
    #14 0x7f213e84a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)

Free it on evsel__exit().
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/20230719202951.534582-2-acme@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/evsel.c

@@ -1474,6 +1474,7 @@ void evsel__exit(struct evsel *evsel)
 	perf_thread_map__put(evsel->core.threads);
 	zfree(&evsel->group_name);
 	zfree(&evsel->name);
+	zfree(&evsel->filter);
 	zfree(&evsel->pmu_name);
 	zfree(&evsel->group_pmu_name);
 	zfree(&evsel->unit);