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/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h
index 7a91943..e6ba25b 100644
--- a/include/media/v4l2-ioctl.h
+++ b/include/media/v4l2-ioctl.h
@@ -284,15 +284,25 @@
 extern long v4l_compat_ioctl32(struct file *file, unsigned int cmd,
 				unsigned long arg);
 
-extern int video_ioctl2(struct inode *inode, struct file *file,
-			unsigned int cmd, unsigned long arg);
-extern long video_ioctl2_unlocked(struct file *file,
-			unsigned int cmd, unsigned long arg);
-
 /* Include support for obsoleted stuff */
 extern int video_usercopy(struct inode *inode, struct file *file,
 			  unsigned int cmd, unsigned long arg,
 			  int (*func)(struct inode *inode, struct file *file,
 				      unsigned int cmd, void *arg));
 
+/* Standard handlers for V4L ioctl's */
+
+/* This prototype is used on fops.unlocked_ioctl */
+extern int __video_ioctl2(struct file *file,
+			unsigned int cmd, unsigned long arg);
+
+/* This prototype is used on fops.ioctl
+ * Since fops.ioctl enables Kernel Big Lock, it is preferred
+ * to use __video_ioctl2 instead.
+ * It should be noticed that there's no lock code inside
+ * video_ioctl2().
+ */
+extern int video_ioctl2(struct inode *inode, struct file *file,
+			unsigned int cmd, unsigned long arg);
+
 #endif /* _V4L2_IOCTL_H */