clocksource/drivers/cadence_ttc: Fix memory leak in ttc_setup_clockevent()

If clk_notifier_register() failed, ttc_setup_clockevent() will return
without freeing 'ttcce', which will leak memory.

Fixes: 70504f31 ("clocksource/drivers/cadence_ttc: Convert init function to return error")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201116135123.2164033-1-yukuai3@huawei.com

drivers/clocksource/timer-cadence-ttc.c

@@ -413,10 +413,8 @@ static int __init ttc_setup_clockevent(struct clk *clk,
 	ttcce->ttc.clk = clk;
 
 	err = clk_prepare_enable(ttcce->ttc.clk);
-	if (err) {
-		kfree(ttcce);
-		return err;
-	}
+	if (err)
+		goto out_kfree;
 
 	ttcce->ttc.clk_rate_change_nb.notifier_call =
 		ttc_rate_change_clockevent_cb;
@@ -426,7 +424,7 @@ static int __init ttc_setup_clockevent(struct clk *clk,
 				    &ttcce->ttc.clk_rate_change_nb);
 	if (err) {
 		pr_warn("Unable to register clock notifier.\n");
-		return err;
+		goto out_kfree;
 	}
 
 	ttcce->ttc.freq = clk_get_rate(ttcce->ttc.clk);
@@ -455,15 +453,17 @@ static int __init ttc_setup_clockevent(struct clk *clk,
 
 	err = request_irq(irq, ttc_clock_event_interrupt,
 			  IRQF_TIMER, ttcce->ce.name, ttcce);
-	if (err) {
-		kfree(ttcce);
-		return err;
-	}
+	if (err)
+		goto out_kfree;
 
 	clockevents_config_and_register(&ttcce->ce,
 			ttcce->ttc.freq / PRESCALE, 1, 0xfffe);
 
 	return 0;
+
+out_kfree:
+	kfree(ttcce);
+	return err;
 }
 
 static int __init ttc_timer_probe(struct platform_device *pdev)