clocksource/drivers/dw_apb_timer_of: Add handling for potential memory leak

Add calls to disable the clock and unmap the timer base address in case
of any failures.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210322121844.2271041-1-dinguyen@kernel.org

drivers/clocksource/dw_apb_timer_of.c

@@ -52,18 +52,34 @@ static int __init timer_get_base_and_rate(struct device_node *np,
 		return 0;
 
 	timer_clk = of_clk_get_by_name(np, "timer");
-	if (IS_ERR(timer_clk))
-		return PTR_ERR(timer_clk);
+	if (IS_ERR(timer_clk)) {
+		ret = PTR_ERR(timer_clk);
+		goto out_pclk_disable;
+	}
 
 	ret = clk_prepare_enable(timer_clk);
 	if (ret)
-		return ret;
+		goto out_timer_clk_put;
 
 	*rate = clk_get_rate(timer_clk);
-	if (!(*rate))
-		return -EINVAL;
+	if (!(*rate)) {
+		ret = -EINVAL;
+		goto out_timer_clk_disable;
+	}
 
 	return 0;
+
+out_timer_clk_disable:
+	clk_disable_unprepare(timer_clk);
+out_timer_clk_put:
+	clk_put(timer_clk);
+out_pclk_disable:
+	if (!IS_ERR(pclk)) {
+		clk_disable_unprepare(pclk);
+		clk_put(pclk);
+	}
+	iounmap(*base);
+	return ret;
 }
 
 static int __init add_clockevent(struct device_node *event_timer)