[DLM] fix i_private

> I think you must have an old version of the base kernel as well?
> i_private no longer exists in struct inode, so you'll have to use
> something else,

I have that patch in my stack but didn't send it; for some reason I
thought it was already changed in your git tree.
Signed-off-by: NDavid Teigland <teigland@redhat.com>
Signed-off-by: NSteven Whitehouse <swhiteho@redhat.com>

fs/dlm/debug_fs.c

@@ -301,7 +301,7 @@ static struct file_operations rsb_fops = {
 
 static int waiters_open(struct inode *inode, struct file *file)
 {
-	file->private_data = inode->i_private;
+	file->private_data = inode->u.generic_ip;
 	return 0;
 }