sisusbvga: Fix oops on disconnect.

Remove dev_info call on disconnect. The sisusb_dev pointer may have been
set to zero by sisusb_delete at this point causing an oops.

The message does not provide any extra information over the standard USB
subsystem output so removing it does not affect functionality.
Signed-off-by: NWill Newton <will.newton@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/misc/sisusbvga/sisusb.c

@@ -3264,8 +3264,6 @@ static void sisusb_disconnect(struct usb_interface *intf)
 
 	/* decrement our usage count */
 	kref_put(&sisusb->kref, sisusb_delete);
-
-	dev_info(&sisusb->sisusb_dev->dev, "Disconnected\n");
 }
 
 static struct usb_device_id sisusb_table [] = {