usb: hid: obtain the requested length from wLength
usb: hid: obtain the requested length from wLength

Obtain the requested length from wLength and assign the
possible length to len argument.

Signed-off-by: Johann Fischer <64a5f06fca6b2d93d742efe564789153170f6198@nordicsemi.no>

zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr