usb: isp1760: remove debug message as error

Remove debug message leftover from the boot error buffer.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Link: https://lore.kernel.org/r/20210727100516.4190681-2-rui.silva@linaro.org


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