clocksource/drivers/versatile: Convert init function to return error

The init functions do not return any error. They behave as the following:

  - panic, thus leading to a kernel crash while another timer may work and
       make the system boot up correctly

  or

  - print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>

drivers/clocksource/versatile.c

@@ -25,18 +25,20 @@ static u64 notrace versatile_sys_24mhz_read(void)
 	return readl(versatile_sys_24mhz);
 }
 
-static void __init versatile_sched_clock_init(struct device_node *node)
+static int __init versatile_sched_clock_init(struct device_node *node)
 {
 	void __iomem *base = of_iomap(node, 0);
 
 	if (!base)
-		return;
+		return -ENXIO;
 
 	versatile_sys_24mhz = base + SYS_24MHZ;
 
 	sched_clock_register(versatile_sys_24mhz_read, 32, 24000000);
+
+	return 0;
 }
-CLOCKSOURCE_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
+CLOCKSOURCE_OF_DECLARE_RET(vexpress, "arm,vexpress-sysreg",
 		       versatile_sched_clock_init);
-CLOCKSOURCE_OF_DECLARE(versatile, "arm,versatile-sysreg",
+CLOCKSOURCE_OF_DECLARE_RET(versatile, "arm,versatile-sysreg",
 		       versatile_sched_clock_init);