staging: vt6556: Replace printk by dev_warn

This patch fixes a checkpatch warning by replacing printk
by dev_warn. Tested by compilation only.
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/main_usb.c

@@ -534,7 +534,8 @@ static void usb_device_reset(struct vnt_private *pDevice)
 
 	status = usb_reset_device(pDevice->usb);
 	if (status)
-            printk("usb_device_reset fail status=%d\n",status);
+		dev_warn(&pDevice->usb->dev,
+			 "usb_device_reset fail status=%d\n", status);
 	return ;
 }