usb: gadget: renesas_usb3: validate endpoint index in standard request handlers

In the Linux kernel, the following vulnerability has been resolved:

usb: gadget: renesas_usb3: validate endpoint index in standard request handlers

The GET_STATUS and SET/CLEAR_FEATURE handlers extract the endpoint

number from the host-supplied wIndex without any sort of validation.

Fix this up by validating the number of endpoints actually match up with

the number the device has before attempting to dereference a pointer

based on this math.

This is just like what was done in commit ee0d382feb44 ("usb: gadget:

aspeed_udc: validate endpoint index for ast udc") for the aspeed driver.