libperf cpumap: Hide/reduce scope of MAX_NR_CPUS

Avoid redefinition of MAX_NR_CPUS as a global constant, the original
definition is tools/perf/perf.h.

Reviewed-by: Leo Yan <[e-mail]>
Signed-off-by: Ian Rogers <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Ben Gainey <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: Kyle Meyer <[e-mail]>
Cc: Mark Rutland <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/lib/perf/cpumap.c

···
 #include <limits.h>
 #include "internal.h"
 
+#define MAX_NR_CPUS 4096
+
 void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus)
 {
 	RC_CHK_ACCESS(map)->nr = nr_cpus;

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

···
 	struct perf_cpu	map[];
 };
 
-#ifndef MAX_NR_CPUS
-#define MAX_NR_CPUS	4096
-#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);