perf cpu_map: Use sysfs__read_int in get_{core,socket}_id()

We have the tools/lib/ sysfs__read_int() for that, avoid code
duplication.

Cc: Adrian Hunter <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Kan Liang <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/cpumap.c

···
 		cpu_map__delete(map);
 }
 
-int cpu_map__get_socket_id(int cpu)
+static int cpu__get_topology_int(int cpu, const char *name, int *value)
 {
-	FILE *fp;
-	const char *mnt;
 	char path[PATH_MAX];
-	int socket_id, ret;
-
-	mnt = sysfs__mountpoint();
-	if (!mnt)
-		return -1;
 
 	snprintf(path, PATH_MAX,
-		"%s/devices/system/cpu/cpu%d/topology/physical_package_id",
-		mnt, cpu);
+		"devices/system/cpu/cpu%d/topology/%s", cpu, name);
 
-	fp = fopen(path, "r");
-	if (!fp)
-		return -1;
-	ret = fscanf(fp, "%d", &socket_id);
-	fclose(fp);
+	return sysfs__read_int(path, value);
+}
 
-	return ret == 1 ? socket_id : -1;
+int cpu_map__get_socket_id(int cpu)
+{
+	int value, ret = cpu__get_topology_int(cpu, "physical_package_id", &value);
+	return ret ?: value;
 }
 
 int cpu_map__get_socket(struct cpu_map *map, int idx)
···
 
 int cpu_map__get_core_id(int cpu)
 {
-	FILE *fp;
-	const char *mnt;
-	char path[PATH_MAX];
-	int core_id, ret;
-
-	mnt = sysfs__mountpoint();
-	if (!mnt)
-		return -1;
-
-	snprintf(path, PATH_MAX,
-		"%s/devices/system/cpu/cpu%d/topology/core_id",
-		mnt, cpu);
-
-	fp = fopen(path, "r");
-	if (!fp)
-		return -1;
-	ret = fscanf(fp, "%d", &core_id);
-	fclose(fp);
-
-	return ret == 1 ? core_id : -1;
+	int value, ret = cpu__get_topology_int(cpu, "core_id", &value);
+	return ret ?: value;
 }
 
 int cpu_map__get_core(struct cpu_map *map, int idx)