tools / cpupower: Fix no idle state information return value

sysfs_get_idlestate_count() returns an unsigned int.  Returning -ENODEV
is not the right thing to do here, and in any case is handled the same
way as if there are no states found.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

tools/power/cpupower/utils/helpers/sysfs.c

@@ -361,7 +361,7 @@ unsigned int sysfs_get_idlestate_count(unsigned int cpu)
 
 	snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU "cpuidle");
 	if (stat(file, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))
-		return -ENODEV;
+		return 0;
 
 	snprintf(file, SYSFS_PATH_MAX, PATH_TO_CPU "cpu%u/cpuidle/state0", cpu);
 	if (stat(file, &statbuf) != 0 || !S_ISDIR(statbuf.st_mode))