USB: core: remove set but not used variable 'udev'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/usb/core/driver.c: In function 'usb_driver_claim_interface':
drivers/usb/core/driver.c:513:21: warning:
 variable 'udev' set but not used [-Wunused-but-set-variable]

Since commit c183813fcee44a24 ("USB: remove LPM management from
usb_driver_claim_interface()"), 'udev' is not used.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/driver.c

@@ -510,7 +510,6 @@ int usb_driver_claim_interface(struct usb_driver *driver,
 				struct usb_interface *iface, void *priv)
 {
 	struct device *dev;
-	struct usb_device *udev;
 	int retval = 0;
 
 	if (!iface)
@@ -524,8 +523,6 @@ int usb_driver_claim_interface(struct usb_driver *driver,
 	if (!iface->authorized)
 		return -ENODEV;
 
-	udev = interface_to_usbdev(iface);
-
 	dev->driver = &driver->drvwrap.driver;
 	usb_set_intfdata(iface, priv);
 	iface->needs_binding = 0;