perf bench: Run inject-build-id with --buildid-all option too

For comparison, it now runs the benchmark twice - one if regular -b and
another for --buildid-all.

  $ perf bench internals inject-build-id
  # Running 'internals/inject-build-id' benchmark:
    Average build-id injection took: 21.002 msec (+- 0.172 msec)
    Average time per event: 2.059 usec (+- 0.017 usec)
    Average memory usage: 8169 KB (+- 0 KB)
    Average build-id-all injection took: 19.543 msec (+- 0.124 msec)
    Average time per event: 1.916 usec (+- 0.012 usec)
    Average memory usage: 7348 KB (+- 0 KB)

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20201012070214.2074921-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>