cpupower: Fix number of idle states

The number of idle states was wrong.
The POLL idle state (on X86) was missed out:
Number of idle states: 4
Available idle states: C1-NHM C3-NHM C6-NHM

While the POLL is not a real idle state, its
statistics should still be shown. It's now also
explained in a detailed manpage.
This should fix a bug of missing the first idle
state on other archs.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

tools/power/cpupower/utils/cpuidle-info.c

@@ -43,9 +43,8 @@ static void cpuidle_cpu_output(unsigned int cpu, int verbose)
 	}
 
 	printf(_("Number of idle states: %d\n"), idlestates);
-
 	printf(_("Available idle states:"));
-	for (idlestate = 1; idlestate < idlestates; idlestate++) {
+	for (idlestate = 0; idlestate < idlestates; idlestate++) {
 		tmp = sysfs_get_idlestate_name(cpu, idlestate);
 		if (!tmp)
 			continue;
@@ -57,7 +56,7 @@ static void cpuidle_cpu_output(unsigned int cpu, int verbose)
 	if (!verbose)
 		return;
 
-	for (idlestate = 1; idlestate < idlestates; idlestate++) {
+	for (idlestate = 0; idlestate < idlestates; idlestate++) {
 		tmp = sysfs_get_idlestate_name(cpu, idlestate);
 		if (!tmp)
 			continue;