ALSA: compress: fix the return value for SNDRV_COMPRESS_VERSION

the return value of SNDRV_COMPRESS_VERSION always return default -ENOTTY as the
return value was never updated for this call
assign return value from put_user()

Reported-by: Haynes <[e-mail]>
CC: [e-mail]
Signed-off-by: Vinod Koul <[e-mail]>
Signed-off-by: Takashi Iwai <[e-mail]>

sound/core/compress_offload.c

···
 	mutex_lock(&stream->device->lock);
 	switch (_IOC_NR(cmd)) {
 	case _IOC_NR(SNDRV_COMPRESS_IOCTL_VERSION):
-		put_user(SNDRV_COMPRESS_VERSION,
+		retval = put_user(SNDRV_COMPRESS_VERSION,
 				(int __user *)arg) ? -EFAULT : 0;
 		break;
 	case _IOC_NR(SNDRV_COMPRESS_GET_CAPS):