Problem: Wrong padding for pum "kind" with 'rightleft'.
Solution: Fix off-by-one error (zeertzjq).
The screen_fill() above is end-exclusive, and
- With 'rightleft' it fills `pum_col - pum_base_width - n + 1` to `col`,
so the next `col` should be `pum_col - pum_base_width - n`.
- With 'norightleft' it fills `col` to `pum_col - pum_base_width + n - 1`,
so the next `col` should be `pum_col - pum_base_width + n`.
closes: vim/vim#15004a2324373eb