ALSA: control: Fix missing return value comments for kernel docs

Each kernel doc comment expects the definition of the return value in
proper format.  This patch adds or fixes the missing entries for
control API.

Link: https://lore.kernel.org/r/20220713104759.4365-6-tiwai@suse.de


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