drivers/rtc/rtc-twl.c: return correct RTC event from ISR

Following changes are made as part of this change:

1. As TWL RTC supports periodic interrupt, the correct event should be
   RTC_PF instead of RTC_UF.

2. No need to initialize variable "events" to 0 & then OR it with the
   event values.  Hence fixing it.
Signed-off-by: NVenu Byravarasu <vbyravarasu@nvidia.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-twl.c

@@ -365,7 +365,7 @@ static int twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 
 static irqreturn_t twl_rtc_interrupt(int irq, void *rtc)
 {
-	unsigned long events = 0;
+	unsigned long events;
 	int ret = IRQ_NONE;
 	int res;
 	u8 rd_reg;
@@ -380,9 +380,9 @@ static irqreturn_t twl_rtc_interrupt(int irq, void *rtc)
 	 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
 	 */
 	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
-		events |= RTC_IRQF | RTC_AF;
+		events = RTC_IRQF | RTC_AF;
 	else
-		events |= RTC_IRQF | RTC_UF;
+		events = RTC_IRQF | RTC_PF;
 
 	res = twl_rtc_write_u8(BIT_RTC_STATUS_REG_ALARM_M,
 				   REG_RTC_STATUS_REG);