VFS: repack DENTRY_ flags.

Bits 13, 23, 24, and 27 are not used.  Move all those holes to the end.

Signed-off-by: NeilBrown <neilb@suse.de>
Link: https://lore.kernel.org/r/20250206054504.2950516-7-neilb@suse.de


Signed-off-by: Christian Brauner <brauner@kernel.org>