i2c-cpm: drop NO_IRQ

Drop NO_IRQ as 0 is the preferred way to describe 'no irq'
(http://lkml.org/lkml/2005/11/21/221). This change is safe, as the driver is
only used on powerpc, where NO_IRQ is 0 anyhow.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Jochen Friedrich <jochen@scram.de>
Cc: Ben Dooks <ben-linux@fluff.org>

drivers/i2c/busses/i2c-cpm.c

@@ -441,7 +441,7 @@ static int __devinit cpm_i2c_setup(struct cpm_i2c *cpm)
 	init_waitqueue_head(&cpm->i2c_wait);
 
 	cpm->irq = of_irq_to_resource(ofdev->node, 0, NULL);
-	if (cpm->irq == NO_IRQ)
+	if (!cpm->irq)
 		return -EINVAL;
 
 	/* Install interrupt handler. */