UPSTREAM: USB: option: fix memory leak

UPSTREAM: USB: option: fix memory leak

Fix memory leak introduced by commit 383cedc3bb435de7a2 ("USB: serial:
full autosuspend support for the option driver") which allocates
usb-serial data but never frees it.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b9c3aab315b51f81649a0d737c4c73783fbd8de0)

Change-Id: I21100086dfb256d5f7b2d14ee9b92b6bf1ae086e
Signed-off-by: Ben Chan <benchan@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/35407
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>