swrasterizer: remove invalid TODO

This function is called in clipping, before the pespective divide, and is not used in later rasterization. Thus it doesn't need perspective correction.

src/video_core/swrasterizer/rasterizer.h

@@ -19,10 +19,9 @@ struct Vertex : Shader::OutputVertex {
 
     // Linear interpolation
     // factor: 0=this, 1=vtx
+    // Note: This function cannot be called after perspective divide
     void Lerp(float24 factor, const Vertex& vtx) {
         pos = pos * factor + vtx.pos * (float24::FromFloat32(1) - factor);
-
-        // TODO: Should perform perspective correct interpolation here...
         quat = quat * factor + vtx.quat * (float24::FromFloat32(1) - factor);
         color = color * factor + vtx.color * (float24::FromFloat32(1) - factor);
         tc0 = tc0 * factor + vtx.tc0 * (float24::FromFloat32(1) - factor);
@@ -30,12 +29,11 @@ struct Vertex : Shader::OutputVertex {
         tc0_w = tc0_w * factor + vtx.tc0_w * (float24::FromFloat32(1) - factor);
         view = view * factor + vtx.view * (float24::FromFloat32(1) - factor);
         tc2 = tc2 * factor + vtx.tc2 * (float24::FromFloat32(1) - factor);
-
-        screenpos = screenpos * factor + vtx.screenpos * (float24::FromFloat32(1) - factor);
     }
 
     // Linear interpolation
     // factor: 0=v0, 1=v1
+    // Note: This function cannot be called after perspective divide
     static Vertex Lerp(float24 factor, const Vertex& v0, const Vertex& v1) {
         Vertex ret = v0;
         ret.Lerp(factor, v1);