ALSA: usb-audio: scarlett2: Remove interrupt debug message

Just ignore instead of printing an error if the interrupt data is not
the expected length. This check was for development and the condition
has not been observed.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/20210620164632.GA9186@m.b4.vu


Signed-off-by: Takashi Iwai <tiwai@suse.de>