V4L/DVB (9331): Remove unused inode parameter from video_ioctl2

inode is never used on video_ioctl2. Remove it and rename the function to
__video_ioctl2. This allows its usage directly as a callback at
fops.unlocked_ioctl.

Since we still need a callback with inode to be used with fops.ioctl,
this patch adds video_ioctl2() that is just a call to __video_ioctl2().

Also, this patch adds some comments about video_ioctl2 and __video_ioctl2
usage at v4l2-ioctl.h.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index 5b3e251..710e1a4 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -1768,7 +1768,7 @@
 	return ret;
 }
 
-int video_ioctl2(struct inode *inode, struct file *file,
+int __video_ioctl2(struct file *file,
 	       unsigned int cmd, unsigned long arg)
 {
 	char	sbuf[128];
@@ -1860,11 +1860,11 @@
 	kfree(mbuf);
 	return err;
 }
-EXPORT_SYMBOL(video_ioctl2);
+EXPORT_SYMBOL(__video_ioctl2);
 
-long video_ioctl2_unlocked(struct file *file,
-		 unsigned int cmd, unsigned long arg)
+int video_ioctl2(struct inode *inode, struct file *file,
+	       unsigned int cmd, unsigned long arg)
 {
-	return video_ioctl2(file->f_path.dentry->d_inode, file, cmd, arg);
+	return __video_ioctl2(file, cmd, arg);
 }
-EXPORT_SYMBOL(video_ioctl2_unlocked);
+EXPORT_SYMBOL(video_ioctl2);