Input: acecad - simplify usb_acecad_disconnect()

There is no need to check whether acecad structure is attached to the
interface; if it isn't and we are called we have much bigger problems.
Also no need to call usb_kill_urb() in usb_acecad_disconnect() since
it is being called in usb_acecad_close().

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/tablet/acecad.c b/drivers/input/tablet/acecad.c
index 265753c..1697ec2 100644
--- a/drivers/input/tablet/acecad.c
+++ b/drivers/input/tablet/acecad.c
@@ -252,13 +252,11 @@
 	struct usb_acecad *acecad = usb_get_intfdata(intf);
 
 	usb_set_intfdata(intf, NULL);
-	if (acecad) {
-		usb_kill_urb(acecad->irq);
-		input_unregister_device(acecad->input);
-		usb_free_urb(acecad->irq);
-		usb_buffer_free(interface_to_usbdev(intf), 8, acecad->data, acecad->data_dma);
-		kfree(acecad);
-	}
+
+	input_unregister_device(acecad->input);
+	usb_free_urb(acecad->irq);
+	usb_buffer_free(acecad->usbdev, 8, acecad->data, acecad->data_dma);
+	kfree(acecad);
 }
 
 static struct usb_device_id usb_acecad_id_table [] = {