usb: host: fotg210: fix the actual_length of an iso packet

We should acquire the actual_length of an iso packet
from the iTD directly using FOTG210_ITD_LENGTH() macro.

Signed-off-by: Kelly Devilliv <kelly.devilliv@gmail.com>
Link: https://lore.kernel.org/r/20210627125747.127646-4-kelly.devilliv@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>