USB: misc: fixup smatch WARNING

This patch fixes the warning,

6a099c63 [4/10] USB: misc: Add USB3503 High-Speed Hub Controller

drivers/usb/misc/usb3503.c:238 usb3503_probe() error: we previously assumed 'pdata' could be null (see line 196)

Signed-off-by: Dongjin Kim <tobetter@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>