drivers/rtc/rtc-cmos.c: propagate hpet_register_irq_handler() failure

If hpet_register_irq_handler() fails, cmos_do_probe() will incorrectly
return 0.
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-cmos.c

@@ -756,11 +756,9 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 		irq_handler_t rtc_cmos_int_handler;
 
 		if (is_hpet_enabled()) {
-			int err;
-
 			rtc_cmos_int_handler = hpet_rtc_interrupt;
-			err = hpet_register_irq_handler(cmos_interrupt);
-			if (err != 0) {
+			retval = hpet_register_irq_handler(cmos_interrupt);
+			if (retval) {
 				dev_warn(dev, "hpet_register_irq_handler "
 						" failed in rtc_init().");
 				goto cleanup1;