ASoC: imx-audmix: check return value of devm_kasprintf()

devm_kasprintf() returns a pointer to dynamically allocated memory.
Pointer could be NULL in case allocation fails. Check pointer validity.
Identified with coccinelle (kmerr.cocci script).

Fixes: b86ef5367761 ("ASoC: fsl: Add Audio Mixer machine driver")
Signed-off-by: Claudiu Beznea <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/fsl/imx-audmix.c

···
 
 		dai_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s%s",
 					  fe_name_pref, args.np->full_name + 1);
+		if (!dai_name)
+			return -ENOMEM;
 
 		dev_info(pdev->dev.parent, "DAI FE name:%s\n", dai_name);
 
···
 			capture_dai_name =
 				devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s %s",
 					       dai_name, "CPU-Capture");
+			if (!capture_dai_name)
+				return -ENOMEM;
 		}
 
 		/*
···
 				       "AUDMIX-Playback-%d", i);
 		be_cp = devm_kasprintf(&pdev->dev, GFP_KERNEL,
 				       "AUDMIX-Capture-%d", i);
+		if (!be_name || !be_pb || !be_cp)
+			return -ENOMEM;
 
 		priv->dai[num_dai + i].cpus	= &dlc[1];
 		priv->dai[num_dai + i].codecs	= &asoc_dummy_dlc;
···
 		priv->dapm_routes[i].source =
 			devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s %s",
 				       dai_name, "CPU-Playback");
+		if (!priv->dapm_routes[i].source)
+			return -ENOMEM;
+
 		priv->dapm_routes[i].sink = be_pb;
 		priv->dapm_routes[num_dai + i].source   = be_pb;
 		priv->dapm_routes[num_dai + i].sink     = be_cp;