clocksource/drivers: Fix uninitialized variable use in timer_of_init

If none of the flags are set, 'ret' is uninitialized as pointed out
by gcc:

drivers/clocksource/timer-of.c: In function 'timer_of_init':
drivers/clocksource/timer-of.c:160:9: error: 'ret' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Since calling the function without any of the flags is an error,
set the return value to -EINVAL for that case.

[ tglx: Get rid of the silly backwards goto while at it ]

Fixes: dc11bae78529 ("clocksource/drivers: Add timer-of common init routine")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/20170621215005.3870011-1-arnd@arndb.de

drivers/clocksource/timer-of.c

@@ -130,7 +130,7 @@ static __init int timer_base_init(struct device_node *np,
 
 int __init timer_of_init(struct device_node *np, struct timer_of *to)
 {
-	int ret;
+	int ret = -EINVAL;
 	int flags = 0;
 
 	if (to->flags & TIMER_OF_BASE) {
@@ -156,7 +156,6 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
 
 	if (!to->clkevt.name)
 		to->clkevt.name = np->name;
-out:
 	return ret;
 
 out_fail:
@@ -168,5 +167,5 @@ out_fail:
 
 	if (flags & TIMER_OF_BASE)
 		timer_base_exit(&to->of_base);
-	goto out;
+	return ret;
 }