ASoC: audio-graph-card2: remove unneeded of_node_get()

"lnk" is used as "port0", and it will be used to get "port1" by
of_get_next_child(ports, lnk). It will call of_node_put() inside. This
function is calling of_node_get() to make up for it, but it doesn't call
paired of_node_put(port0) when it quit function.
This of_node_get() itself is not needed, let's remove it.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87jzk3akoo.wl-kuninori.morimoto.gx@renesas.com


Signed-off-by: Mark Brown <broonie@kernel.org>