ALSA: info - Implement common llseek for binary mode

The llseek implementation is identical for existing driver implementations,
so let's merge to the common layer.  The same code for the text proc file
can be used even for the binary proc file.

The driver can provide its own llseek method if needed.  Then the common
code will be skipped.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/isa/gus/gus_mem_proc.c

@@ -46,31 +46,6 @@ static ssize_t snd_gf1_mem_proc_dump(struct snd_info_entry *entry,
 	return count;
 }			
 
-static loff_t snd_gf1_mem_proc_llseek(struct snd_info_entry *entry,
-				      void *private_file_data,
-				      struct file *file,
-				      loff_t offset, int orig)
-{
-	struct gus_proc_private *priv = entry->private_data;
-
-	switch (orig) {
-	case SEEK_SET:
-		file->f_pos = offset;
-		break;
-	case SEEK_CUR:
-		file->f_pos += offset;
-		break;
-	case SEEK_END: /* offset is negative */
-		file->f_pos = priv->size + offset;
-		break;
-	default:
-		return -EINVAL;
-	}
-	if (file->f_pos > priv->size)
-		file->f_pos = priv->size;
-	return file->f_pos;
-}
-
 static void snd_gf1_mem_proc_free(struct snd_info_entry *entry)
 {
 	struct gus_proc_private *priv = entry->private_data;
@@ -79,7 +54,6 @@ static void snd_gf1_mem_proc_free(struct snd_info_entry *entry)
 
 static struct snd_info_entry_ops snd_gf1_mem_proc_ops = {
 	.read = snd_gf1_mem_proc_dump,
-	.llseek = snd_gf1_mem_proc_llseek,
 };
 
 int snd_gf1_mem_proc_init(struct snd_gus_card * gus)