max17042_battery: Fix driver exit function

This patch fixes driver's remove function: it should free the IRQ.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

drivers/power/max17042_battery.c

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index 39dd610..93fd13c 100644
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -715,6 +715,8 @@
 {
 	struct max17042_chip *chip = i2c_get_clientdata(client);
 
+	if (client->irq)
+		free_irq(client->irq, chip);
 	power_supply_unregister(&chip->battery);
 	return 0;
 }