ASoC: simple-card-utils: Avoid NULL deref in asoc_simple_set_tdm()

Don't dereference simple_dai before it has been checked for NULL.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: 1e974e5b82 ("ASoC: audio_graph_card2: Add support for variable slot widths")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20220404113252.1152659-1-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/simple-card-utils.c

@@ -364,13 +364,15 @@ static int asoc_simple_set_tdm(struct snd_soc_dai *dai,
 				struct snd_pcm_hw_params *params)
 {
 	int sample_bits = params_width(params);
-	int slot_width = simple_dai->slot_width;
-	int slot_count = simple_dai->slots;
+	int slot_width, slot_count;
 	int i, ret;
 
 	if (!simple_dai || !simple_dai->tdm_width_map)
 		return 0;
 
+	slot_width = simple_dai->slot_width;
+	slot_count = simple_dai->slots;
+
 	if (slot_width == 0)
 		slot_width = sample_bits;