phy: cpcap-usb: Fix platform_get_irq_byname's error checking.

The platform_get_irq_byname() function returns negative if an error occurs.
zero or positive number on success. platform_get_irq_byname() error
checking for zero is not correct.

Fixes: 6d6ce40f63af ("phy: cpcap-usb: Add CPCAP PMIC USB support")
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
diff --git a/drivers/phy/motorola/phy-cpcap-usb.c b/drivers/phy/motorola/phy-cpcap-usb.c
index accaaac..6601ad0 100644
--- a/drivers/phy/motorola/phy-cpcap-usb.c
+++ b/drivers/phy/motorola/phy-cpcap-usb.c
@@ -310,7 +310,7 @@
 	int irq, error;
 
 	irq = platform_get_irq_byname(pdev, name);
-	if (!irq)
+	if (irq < 0)
 		return -ENODEV;
 
 	error = devm_request_threaded_irq(ddata->dev, irq, NULL,