[ALSA] sound: aoa of_node_put and kfree cleanup

This patch removes redundant argument checks for of_node_put() and kfree().
Acked-by: Johannes Berg <johannes@sipsolutions.net>

Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>