Revert xorigin and yorigin to usize
Revert xorigin and yorigin to usize

The type of fields xorigin and yorigin was changed from usize to isize
only for Plane::window(), which has now been removed.

Plane origins may not be negative, so revert their type to usize.

This partially reverts 1bd94a2d4b782446ae4be8645c46136cc988af1f.

xiph/rav1e,xiph/rav1e