commit 472d7e55 upstream.

The interrupt URB is killed at final port close since commit
0de9a702 ("USB: overhaul of mos7840 driver").

Fixes: 0de9a702 ("USB: overhaul of mos7840 driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>