Using usb_unlink_urb can cause iforce_open to fail when called
soon after iforce_release. Also updated my email address and
replaced calls to printk() by dbg(), warn(), info(), err()...
Signed-off-by: NJohann Deneux <johann.deneux@gmail.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>