libperf: Make perf_cpu_map__alloc() available as an internal function for tools/perf to use

We had the open coded equivalent in perf_cpu_map__empty_new(), so reuse
what is in libperf.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Stephen Brennan <stephen.s.brennan@oracle.com>
Link: https://lore.kernel.org/lkml/20230407230405.2931830-3-irogers@google.com
[ Split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/perf/cpumap.c

@@ -10,7 +10,7 @@
 #include <ctype.h>
 #include <limits.h>
 
-static struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
+struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus)
 {
 	struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus);
 

tools/lib/perf/include/internal/cpumap.h

@@ -24,6 +24,7 @@ struct perf_cpu_map {
 #define MAX_NR_CPUS	2048
 #endif
 
+struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus);
 int perf_cpu_map__idx(const struct perf_cpu_map *cpus, struct perf_cpu cpu);
 bool perf_cpu_map__is_subset(const struct perf_cpu_map *a, const struct perf_cpu_map *b);
 

tools/perf/util/cpumap.c

@@ -160,7 +160,7 @@ size_t cpu_map__fprintf(struct perf_cpu_map *map, FILE *fp)
 
 struct perf_cpu_map *perf_cpu_map__empty_new(int nr)
 {
-	struct perf_cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int) * nr);
+	struct perf_cpu_map *cpus = perf_cpu_map__alloc(nr);
 
 	if (cpus != NULL) {
 		int i;