libperf tests: Update a use of the new cpumap API

libperf tests: Update a use of the new cpumap API

Fixes a build breakage.

Fixes: 446c8a88b5bb1910 ("perf cpumap: Give CPUs their own type")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: colin ian king <colin.king@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Link: http://lore.kernel.org/lkml/20220114065105.1806542-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>