ALSA: echoaudio: remove redundant initialization of pointer 'pipe'

The pointer 'pipe' is being initialized with a value that is never
read and it is re-assigned later, hence the initialization is redundant
and can be removed. Also remove pointer 'runtime' as it is no longer
required.

Cleans up clang warning:
sound/pci/echoaudio/echoaudio.c:740:20: warning: Value stored to 'pipe'
during its initialization is never read
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/pci/echoaudio/echoaudio.c

@@ -736,8 +736,7 @@ static int pcm_prepare(struct snd_pcm_substream *substream)
 static int pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct echoaudio *chip = snd_pcm_substream_chip(substream);
-	struct snd_pcm_runtime *runtime = substream->runtime;
-	struct audiopipe *pipe = runtime->private_data;
+	struct audiopipe *pipe;
 	int i, err;
 	u32 channelmask = 0;
 	struct snd_pcm_substream *s;