USB: option: make interface blacklist work again

commit 0d905fd5 "USB: option: convert Huawei K3765, K4505, K4605
reservered interface to blacklist" accidentally ANDed two
blacklist tests by leaving out a return.  This was not noticed
because the two consecutive bracketless if statements made it
syntactically correct.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Cc: <stable@vger.kernel.org> # 3.2.y, 3.3.y
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>