linux-phytec-fsl

usb: misc: usbtest: improve the description for error message

Now the function of complicated_callback is not only used for iso
transfer, improve the error message to reflect it.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>