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

sound/soc/soc-dapm.c

@@ -3080,11 +3080,11 @@ static int snd_soc_dapm_del_route(struct snd_soc_dapm_context *dapm,
 int snd_soc_dapm_add_routes(struct snd_soc_dapm_context *dapm,
 			    const struct snd_soc_dapm_route *route, int num)
 {
-	int i, r, ret = 0;
+	int i, ret = 0;
 
 	mutex_lock_nested(&dapm->card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME);
 	for (i = 0; i < num; i++) {
-		r = snd_soc_dapm_add_route(dapm, route);
+		int r = snd_soc_dapm_add_route(dapm, route);
 		if (r < 0) {
 			dev_err(dapm->dev, "ASoC: Failed to add route %s -> %s -> %s\n",
 				route->source,