ASoC: au1x: dbdma2: plug memleak in pcm device creation error path

free the allocated pcm platform device in the error path.

Signed-off-by: Manuel Lauss <[e-mail]>
Acked-by: Liam Girdwood <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

sound/soc/au1x/dbdma2.c

···
 	if (!ret)
 		return pd;
 
+	platform_device_put(pd);
 out:
 	kfree(res);
 	return NULL;