Fix the following coccicheck warning:

drivers/usb/core/hub.c:95:12-28: WARNING: Assignment of 0/1 to bool
variable
Signed-off-by: NJason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200426094147.23467-1-yanaijie@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>