ALSA: scarlett2: Formatting fixes

Add missing blank line before comment.

For consistency with other functions that have few parameters, move
the parameters onto the same line as the function name.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/72be568b02eea12621b0c4a96f8e8cc65b0c13c0.1703444932.git.g@b4.vu


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