staging: most: usb: use EINVAL error code

This patch replaces the error code EIO with EINVAL, when there is no IO
happening.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Link: https://lore.kernel.org/r/1588672829-28883-3-git-send-email-christian.gromm@microchip.com


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