rtc: max77686: Fix max77686_rtc_read_alarm() return value

The function is always returning zero even in case of failures since
the ret value was not propagated to the callers. Fix the error path.

Reported-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Javier Martinez Canillas <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Tested-by: Krzysztof Kozlowski <[email protected]>
Acked-by: Laxman Dewangan <[email protected]>
Reviewed-by: Andi Shyti <[email protected]>
Signed-off-by: Alexandre Belloni <[email protected]>
diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
index 7184a0e..6653c3d 100644
--- a/drivers/rtc/rtc-max77686.c
+++ b/drivers/rtc/rtc-max77686.c
@@ -235,7 +235,7 @@
 
 out:
 	mutex_unlock(&info->lock);
-	return 0;
+	return ret;
 }
 
 static int max77686_rtc_stop_alarm(struct max77686_rtc_info *info)