Introduce int ret and check it value after call to usb_register().
Signed-off-by: NAlexey Klimov <klimov.linux@gmail.com>
Signed-off-by: NJean-Francois Moine <moinejf@free.fr>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>