rtc: ds1307: simplify irq setup code

No need to have two seperate if-blocks for setting up the irq.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Tested-by: David Anders <danders.dev@gmail.com>
Cc: Austin Boyle <Austin.Boyle@aviatnet.com>
Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 5098e1a..d4543e8 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -646,11 +646,6 @@
 	case ds_1337:
 	case ds_1339:
 	case ds_3231:
-		/* has IRQ? */
-		if (ds1307->client->irq > 0 && chip->alarm) {
-			INIT_WORK(&ds1307->work, ds1307_work);
-			want_irq = true;
-		}
 		/* get registers that the "rtc" read below won't read... */
 		tmp = ds1307->read_block_data(ds1307->client,
 				DS1337_REG_CONTROL, 2, buf);
@@ -668,10 +663,14 @@
 		 * For some variants, be sure alarms can trigger when we're
 		 * running on Vbackup (BBSQI/BBSQW)
 		 */
-		if (want_irq) {
+		if (ds1307->client->irq > 0 && chip->alarm) {
+			INIT_WORK(&ds1307->work, ds1307_work);
+
 			ds1307->regs[0] |= DS1337_BIT_INTCN
 					| bbsqi_bitpos[ds1307->type];
 			ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
+
+			want_irq = true;
 		}
 
 		i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,