ovl: fix working on distributed fs as lower layer

This adds missing .d_select_inode into alternative dentry_operations.

Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Fixes: 7c03b5d4 ("ovl: allow distributed fs as lower layer")
Fixes: 4bacc9c9 ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Reviewed-by: Nikolay Borisov <kernel@kyup.com>
Tested-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org> # 4.2+