cpufreq: dbx500: call CPUFREQ_POSTCHANGE notfier in error cases

PRECHANGE and POSTCHANGE notifiers must be called in groups, i.e either both
should be called or both shouldn't be.

In case we have started PRECHANGE notifier and found an error, we must call
POSTCHANGE notifier with freqs.new = freqs.old to guarantee that sequence of
calling notifiers is complete.

This patch fixes it.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/cpufreq/dbx500-cpufreq.c

@@ -57,13 +57,13 @@ static int dbx500_cpufreq_target(struct cpufreq_policy *policy,
 	if (ret) {
 		pr_err("dbx500-cpufreq: Failed to set armss_clk to %d Hz: error %d\n",
 		       freqs.new * 1000, ret);
-		return ret;
+		freqs.new = freqs.old;
 	}
 
 	/* post change notification */
 	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
 
-	return 0;
+	return ret;
 }
 
 static unsigned int dbx500_cpufreq_getspeed(unsigned int cpu)