rtc: ds1343: clean up ds1343_nvram_read()/ds1343_nvram_write()

The change removes redundant sysfs binary file boundary checks, since
this task is already done on caller side in fs/sysfs/file.c

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c
index ae9f997..79a06dd 100644
--- a/drivers/rtc/rtc-ds1343.c
+++ b/drivers/rtc/rtc-ds1343.c
@@ -162,12 +162,6 @@
 	struct device *dev = kobj_to_dev(kobj);
 	struct ds1343_priv *priv = dev_get_drvdata(dev);
 
-	if (unlikely(!count))
-		return count;
-
-	if ((count + off) > DS1343_NVRAM_LEN)
-		count = DS1343_NVRAM_LEN - off;
-
 	address = DS1343_NVRAM + off;
 
 	ret = regmap_bulk_write(priv->map, address, buf, count);
@@ -187,12 +181,6 @@
 	struct device *dev = kobj_to_dev(kobj);
 	struct ds1343_priv *priv = dev_get_drvdata(dev);
 
-	if (unlikely(!count))
-		return count;
-
-	if ((count + off) > DS1343_NVRAM_LEN)
-		count = DS1343_NVRAM_LEN - off;
-
 	address = DS1343_NVRAM + off;
 
 	ret = regmap_bulk_read(priv->map, address, buf, count);