usb: phy: fix return value check of usb_get_phy

usb_get_phy will return -ENODEV if it's not able to find the phy. Hence
fixed all the callers of usb_get_phy to check for this error condition
instead of relying on a non-zero value as success condition.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/tusb6010.c b/drivers/usb/musb/tusb6010.c
index 8ddf3d5..1a1bd9c 100644
--- a/drivers/usb/musb/tusb6010.c
+++ b/drivers/usb/musb/tusb6010.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#include <linux/err.h>
 #include <linux/init.h>
 #include <linux/prefetch.h>
 #include <linux/usb.h>
@@ -1079,7 +1080,7 @@
 
 	usb_nop_xceiv_register();
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
-	if (!musb->xceiv)
+	if (IS_ERR_OR_NULL(musb->xceiv))
 		return -ENODEV;
 
 	pdev = to_platform_device(musb->controller);