This is in preparation for the routine starting to zero the field.

De facto coded by Dave Chinner, see:
https://lore.kernel.org/linux-fsdevel/ZmgtaGglOL33Wkzr@dread.disaster.area/Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20240611120626.513952-2-mjguzik@gmail.comSigned-off-by: Christian Brauner <brauner@kernel.org>