uboot-imx

usb: gadget: fastboot: Request status and length check in rx handler

This avoids handling requests that have an error status or no data.
In particular, this avoids showing unnecessary error messages when the USB
gadget gets disconnected (e.g. with fastboot continue) and the fastboot USB
gadget driver sends an error back to the host (that has disconnected already).

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>