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.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>