VideoCommon: drop UpdateViewportWithCorrection

It's only used once in BPFunction which itself is also only used once.
So the setter is moved to BPStructs like all other ones.

Source/Core/VideoCommon/Src/VertexShaderManager.h

@@ -12,8 +12,6 @@ class PointerWrap;
 
 void UpdateProjectionHack(int iParams[], std::string sParams[]);
 
-void UpdateViewportWithCorrection();
-
 // The non-API dependent parts.
 class VertexShaderManager
 {