perf test: Fix a thread map leak in thread_map_synthesize test

perf test: Fix a thread map leak in thread_map_synthesize test

It missed to call perf_thread_map__put() after using the map.

  $ perf test -v 43
  43: Synthesize thread map                      :
  --- start ---
  test child forked, pid 162640

  =================================================================
  ==162640==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 32 byte(s) in 1 object(s) allocated from:
    #0 0x7fd48cdaa1f8 in __interceptor_realloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:164
    #1 0x563e6d5f8d0e in perf_thread_map__realloc /home/namhyung/project/linux/tools/lib/perf/threadmap.c:23
    #2 0x563e6d3ef69a in thread_map__new_by_pid util/thread_map.c:46
    #3 0x563e6d2cec90 in test__thread_map_synthesize tests/thread-map.c:97
    #4 0x563e6d27d8fb in run_test tests/builtin-test.c:428
    #5 0x563e6d27d8fb in test_and_print tests/builtin-test.c:458
    #6 0x563e6d27fa53 in __cmd_test tests/builtin-test.c:679
    #7 0x563e6d27fa53 in cmd_test tests/builtin-test.c:825
    #8 0x563e6d2ebce4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:313
    #9 0x563e6d175a88 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:365
    #10 0x563e6d175a88 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:409
    #11 0x563e6d175a88 in main /home/namhyung/project/linux/tools/perf/perf.c:539
    #12 0x7fd48c8dfd09 in __libc_start_main ../csu/libc-start.c:308

  SUMMARY: AddressSanitizer: 8224 byte(s) leaked in 2 allocation(s).
  test child finished with 1
  ---- end ----
  Synthesize thread map: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210301140409.184570-9-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>