PixelShaderGen: always run indirect stage logic

Hardware testing has confirmed that fb_addprev and wrapping both run even when the indirect stage is disabled.

Source/Core/VideoCommon/PixelShaderGen.h

@@ -133,6 +133,7 @@ struct pixel_shader_uid_data
     u32 pad1 : 6;
 
     // TODO: Clean up the swapXY mess
+    // TODO: remove hasindstage, as it no longer does anything useful
     u32 hasindstage : 1;
     u32 tevind : 21;
     u32 tevksel_swap1a : 2;