[CPUFREQ] state info wrong after resume

Sometimes old_index != stat->last_index, see cpufreq_update_policy, bios can
change cpu setting in resume.  In my test, after resume cpu is in lowest
speed, but the stat info shows cpu is in full speed.  This patch makes the
stat info correct after a resume.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Jones <davej@redhat.com>

drivers/cpufreq/cpufreq_stats.c

@@ -288,7 +288,7 @@ cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
 	if (!stat)
 		return 0;
 
-	old_index = freq_table_get_index(stat, freq->old);
+	old_index = stat->last_index;
 	new_index = freq_table_get_index(stat, freq->new);
 
 	cpufreq_stats_update(freq->cpu);