ASoC: soc-core: cleanup cppcheck warning at snd_soc_of_parse_audio_routing()

This patch cleanups below cppcheck warning.

sound/soc/soc-core.c:2931:9: style: The scope of the variable 'ret' can be reduced. [variableScope]
 int i, ret;
        ^

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87o8alyl67.wl-kuninori.morimoto.gx@renesas.com


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