Blender Git Loki

Fix T89265: Crash when tabbing through num inputs

Fix by reverting the part of ec30cf0b742f5181c4de91b474ca01d6a809c593
that assigned `but->editval` in `ui_numedit_begin_set_values`.

Causing access freed memory when using tab to switch
to a numeric input and then leaving the textbox by clicking outside.
This was because `ui_numedit_begin_set_values` shouldn't need to set
`but->editval` and overwrite the pointer.
This would set a pointer that had previously been freed,
causing a `NULL` check to fail later on.

Ref D11679