cpufreq: cpufreq-cpu0: Call CPUFREQ_POSTCHANGE notifier for failure cases too

Currently we are simply returning from target() if we encounter some error after
broadcasting CPUFREQ_PRECHANGE notifier. Which looks to be wrong as others might
depend on POSTCHANGE notifier for their functioning.

So, better broadcast CPUFREQ_POSTCHANGE notifier for these failure cases too,
but with old frequency.

Signed-off-by: Viresh Kumar <[e-mail]>
Acked-by: Shawn Guo <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/cpufreq/cpufreq-cpu0.c

···
 		if (IS_ERR(opp)) {
 			rcu_read_unlock();
 			pr_err("failed to find OPP for %ld\n", freq_Hz);
-			return PTR_ERR(opp);
+			freqs.new = freqs.old;
+			ret = PTR_ERR(opp);
+			goto post_notify;
 		}
 		volt = opp_get_voltage(opp);
 		rcu_read_unlock();
···
 		if (ret) {
 			pr_err("failed to scale voltage up: %d\n", ret);
 			freqs.new = freqs.old;
-			return ret;
+			goto post_notify;
 		}
 	}
 
···
 		pr_err("failed to set clock rate: %d\n", ret);
 		if (cpu_reg)
 			regulator_set_voltage_tol(cpu_reg, volt_old, tol);
-		return ret;
+		freqs.new = freqs.old;
+		goto post_notify;
 	}
 
 	/* scaling down?  scale voltage after frequency */
···
 			pr_err("failed to scale voltage down: %d\n", ret);
 			clk_set_rate(cpu_clk, freqs.old * 1000);
 			freqs.new = freqs.old;
-			return ret;
 		}
 	}
 
+post_notify:
 	for_each_online_cpu(cpu) {
 		freqs.cpu = cpu;
 		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
 	}
 
-	return 0;
+	return ret;
 }
 
 static int cpu0_cpufreq_init(struct cpufreq_policy *policy)