clocksource/drivers/timer-of: Check return value of of_iomap in timer_of_base_init()

of_base->base can either be iomapped using of_io_request_and_map() or
of_iomap() depending whether or not an of_base->name has been set.

Thus check of_base->base against NULL as of_iomap() does not return a
PTR_ERR() in case of error.

Fixes: 9aea417a ("clocksource/drivers/timer-of: Don't request the resource by name")
Signed-off-by: NGuillaume Ranquet <granquet@baylibre.com>
Link: https://lore.kernel.org/r/20220307172656.4836-1-granquet@baylibre.comSigned-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/timer-of.c

@@ -157,9 +157,9 @@ static __init int timer_of_base_init(struct device_node *np,
 	of_base->base = of_base->name ?
 		of_io_request_and_map(np, of_base->index, of_base->name) :
 		of_iomap(np, of_base->index);
-	if (IS_ERR(of_base->base)) {
-		pr_err("Failed to iomap (%s)\n", of_base->name);
-		return PTR_ERR(of_base->base);
+	if (IS_ERR_OR_NULL(of_base->base)) {
+		pr_err("Failed to iomap (%s:%s)\n", np->name, of_base->name);
+		return of_base->base ? PTR_ERR(of_base->base) : -ENOMEM;
 	}
 
 	return 0;