ASoC: soc-dapm: cleanup cppcheck warning at snd_soc_dapm_add_routes()

This patch cleanups below cppcheck warning.

sound/soc/soc-dapm.c:3082:9: style: The scope of the variable 'r' can be reduced. [variableScope]
 int i, r, ret = 0;
        ^

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/87mtpwu24b.wl-kuninori.morimoto.gx@renesas.com


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