ASoC: core: Fix pcm code debugfs error

We can have 2 dcpm-s with the same backend and frontend name
(capture + playback pair), this causes the following debugfs error
on Intel Bay Trail systems:

[  298.969049] debugfs: Directory 'SSP2-Codec' with parent 'Baytrail Audio Port' already present!

This commit adds a ":playback" or ":capture" postfix to the debugfs dir
name fixing this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20191005212202.5206-1-hdegoede@redhat.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-pcm.c

@@ -1146,6 +1146,7 @@ static int dpcm_be_connect(struct snd_soc_pcm_runtime *fe,
 {
 	struct snd_soc_dpcm *dpcm;
 	unsigned long flags;
+	char *name;
 
 	/* only add new dpcms */
 	for_each_dpcm_be(fe, stream, dpcm) {
@@ -1171,9 +1172,15 @@ static int dpcm_be_connect(struct snd_soc_pcm_runtime *fe,
 			stream ? "<-" : "->", be->dai_link->name);
 
 #ifdef CONFIG_DEBUG_FS
-	dpcm->debugfs_state = debugfs_create_dir(be->dai_link->name,
+	name = kasprintf(GFP_KERNEL, "%s:%s", be->dai_link->name,
+			 stream ? "capture" : "playback");
+	if (name) {
+		dpcm->debugfs_state = debugfs_create_dir(name,
 							 fe->debugfs_dpcm_root);
-	debugfs_create_u32("state", 0644, dpcm->debugfs_state, &dpcm->state);
+		debugfs_create_u32("state", 0644, dpcm->debugfs_state,
+				   &dpcm->state);
+		kfree(name);
+	}
 #endif
 	return 1;
 }