libperf: Move perf's cpu_map__idx() to perf_cpu_map__idx()

As an internal function that will be used by both perf and libperf, but
is not exported at this point.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190822111141.25823-5-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/lib/cpumap.c

@@ -242,3 +242,15 @@ bool perf_cpu_map__empty(const struct perf_cpu_map *map)
 {
 	return map ? map->map[0] == -1 : true;
 }
+
+int perf_cpu_map__idx(struct perf_cpu_map *cpus, int cpu)
+{
+	int i;
+
+	for (i = 0; i < cpus->nr; ++i) {
+		if (cpus->map[i] == cpu)
+			return i;
+	}
+
+	return -1;
+}

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

@@ -14,4 +14,6 @@ struct perf_cpu_map {
 #define MAX_NR_CPUS	2048
 #endif
 
+int perf_cpu_map__idx(struct perf_cpu_map *cpus, int cpu);
+
 #endif /* __LIBPERF_INTERNAL_CPUMAP_H */