usb: core: check for valid id_table when using the RefId feature

When implementing the RefId feature, it was missed that id_tables can be
NULL under special circumstances. Bail out in that case.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed