ASoC: wm8991: Remove unused pointer in wm8991_probe()

Remove unused pointer 'wm8991' in function wm8991_probe(). The last user
vanished with a86652e5 (ASoC: wm8991: Convert to direct regmap API usage)

Detected by Coverity: CID 1162831
Signed-off-by: Christian Engelmayer <cengelma@gmx.at>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/codecs/wm8991.c

@@ -1251,11 +1251,8 @@ static int wm8991_remove(struct snd_soc_codec *codec)
 
 static int wm8991_probe(struct snd_soc_codec *codec)
 {
-	struct wm8991_priv *wm8991;
 	int ret;
 
-	wm8991 = snd_soc_codec_get_drvdata(codec);
-
 	ret = snd_soc_codec_set_cache_io(codec, 8, 16, SND_SOC_REGMAP);
 	if (ret < 0) {
 		dev_err(codec->dev, "Failed to set cache i/o: %d\n", ret);