i2c: mpc: Fix ISR return value

ISR should not return IRQ_HANDLED for not handling anything.
This patch fixes the return value of ISR for the same case.
Signed-off-by: NAmit Singh Tomar <amit.tomar@freescale.com>
Acked-by: NDanielle Costantino <danielle.costantino@gmail.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-mpc.c

@@ -96,8 +96,9 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
 		i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
 		writeb(0, i2c->base + MPC_I2C_SR);
 		wake_up(&i2c->queue);
+		return IRQ_HANDLED;
 	}
-	return IRQ_HANDLED;
+	return IRQ_NONE;
 }
 
 /* Sometimes 9th clock pulse isn't generated, and slave doesn't release