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

This patch cleanups below cppcheck warning.

sound/soc/soc-core.c:2777:25: style: The scope of the variable 'ret' can be reduced. [variableScope]
 int i, j, num_widgets, ret;
                        ^

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87pmv1yl6b.wl-kuninori.morimoto.gx@renesas.com


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