USB: adutux: fix debugging

[ Upstream commit c56150c1bc8da5524831b1dac2eec3c67b89f587 ]

Handling for removal of the controller was missing at one place.
Add it.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20200917112600.26508-1-oneukum@suse.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>