ALSA: compress: Remove unused variable

Commit 04c5d5a430 ("ALSA: compress: Embed struct device") removed
the statement that used 'str' but didn't remove the variable itself.
So remove it.

[Adding stable to Cc since pr_debug() may refer to the uninitialized
 buffer -- tiwai]

Fixes: 04c5d5a430 ("ALSA: compress: Embed struct device")
Signed-off-by: Guneshwor Singh <guneshwor.o.singh@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/compress_offload.c

@@ -948,14 +948,13 @@ static const struct file_operations snd_compr_file_ops = {
 static int snd_compress_dev_register(struct snd_device *device)
 {
 	int ret = -EINVAL;
-	char str[16];
 	struct snd_compr *compr;
 
 	if (snd_BUG_ON(!device || !device->device_data))
 		return -EBADFD;
 	compr = device->device_data;
 
-	pr_debug("reg %s for device %s, direction %d\n", str, compr->name,
+	pr_debug("reg device %s, direction %d\n", compr->name,
 			compr->direction);
 	/* register compressed device */
 	ret = snd_register_device(SNDRV_DEVICE_TYPE_COMPRESS,