vfs: remove open_flags from d_real()

Opening regular files on overlayfs is now handled via ovl_open().  Remove
the now unused "open_flags" argument from d_op->d_real() and the d_real()
helper.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 24e1a4f..08a36e1 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -21,8 +21,7 @@
 	char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
 	struct vfsmount *(*d_automount)(struct path *path);
 	int (*d_manage)(const struct path *, bool);
-	struct dentry *(*d_real)(struct dentry *, const struct inode *,
-				 unsigned int);
+	struct dentry *(*d_real)(struct dentry *, const struct inode *);
 
 locking rules:
 		rename_lock	->d_lock	may block	rcu-walk