clutter/actor: Remove superfluous line

This sets exactly the same thing as the line above and doesn't
manipulate any parts of the calculation, too, it's most likely a very
old copy-paste mistake, remove it.

Thanks to Rafał Mikrut for discovering it.

Fixes GNOME/mutter#1222

Part-of: <GNOME/mutter!1660>

clutter/clutter/clutter-actor.c

@@ -13428,7 +13428,6 @@ clutter_actor_transform_stage_point (ClutterActor *self,
 
       RQ[0][2] = DET (px, dx2, py, dy2) / det;
       RQ[1][2] = DET (dx1, px, dy1, py) / det;
-      RQ[1][2] = DET (dx1, px, dy1, py) / det;
       RQ[2][2] = 1.0;
       RQ[0][0] = v[1].x - v[0].x + (RQ[0][2] * v[1].x);
       RQ[1][0] = v[2].x - v[0].x + (RQ[1][2] * v[2].x);