The patch is that check if usb_get_dev_index() function return valid
pointer. If valid, continue. Otherwise return -1.
Signed-off-by: Ryan Chen <ryan.chen@st.com>
Acked-by: Markus Klotzbuecher <mk@denx.de>
        /* scan all USB Devices */
        for(i=0;i<USB_MAX_DEVICE;i++) {
                dev=usb_get_dev_index(i); /* get device */
+               if(dev == NULL)
+                       return -1;
                if(dev->devnum!=-1) {
                        if(usb_kbd_probe(dev,0)==1) { /* Ok, we found a keyboard */
                                /* check, if it is already registered */