rtc: tx4939: clean up tx4939_rtc_nvram_read()/tx4939_rtc_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-tx4939.c b/drivers/rtc/rtc-tx4939.c
index cb7f94e..560d9a5 100644
--- a/drivers/rtc/rtc-tx4939.c
+++ b/drivers/rtc/rtc-tx4939.c
@@ -199,8 +199,7 @@
 	ssize_t count;
 
 	spin_lock_irq(&pdata->lock);
-	for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
-	     count++, size--) {
+	for (count = 0; count < size; count++) {
 		__raw_writel(pos++, &rtcreg->adr);
 		*buf++ = __raw_readl(&rtcreg->dat);
 	}
@@ -218,8 +217,7 @@
 	ssize_t count;
 
 	spin_lock_irq(&pdata->lock);
-	for (count = 0; size > 0 && pos < TX4939_RTC_REG_RAMSIZE;
-	     count++, size--) {
+	for (count = 0; count < size; count++) {
 		__raw_writel(pos++, &rtcreg->adr);
 		__raw_writel(*buf++, &rtcreg->dat);
 	}