Revert "vector: Improve the number of segments for a Bézier curve"
Revert "vector: Improve the number of segments for a Bézier curve"

This reverts commit ad2999fa044c87581267cf48baaed882b31617aa.

Reason: Added *2 as a mistake. And without this multiplying, the quarity was not good.

hajimehoshi/ebiten,hajimehoshi/ebiten