Use texcoordStereo instead of UnityStereoTransformScreenSpaceTex

Couple places I had to port.  Incidentally, in the bakers, boo!

Author: robbiesri

PostProcessing/Shaders/Builtins/GrainBaker.shader

@@ -64,15 +64,13 @@ Shader "Hidden/PostProcessing/GrainBaker"
 
         float4 FragGrain(VaryingsDefault i) : SV_Target
         {
-            i.texcoord = UnityStereoTransformScreenSpaceTex(i.texcoord);
-            float grain = Step3BW(i.texcoord * float2(128.0, 128.0));
+            float grain = Step3BW(i.texcoordStereo * float2(128.0, 128.0));
             return float4(grain.xxx, 1.0);
         }
 
         float4 FragGrainColored(VaryingsDefault i) : SV_Target
         {
-            i.texcoord = UnityStereoTransformScreenSpaceTex(i.texcoord);
-            float3 grain = Step3(i.texcoord * float2(128.0, 128.0));
+            float3 grain = Step3(i.texcoordStereo * float2(128.0, 128.0));
             return float4(grain, 1.0);
         }
 

PostProcessing/Shaders/Builtins/Lut2DBaker.shader

@@ -69,7 +69,7 @@ Shader "Hidden/PostProcessing/Lut2DBaker"
         float4 FragLDRFromScratch(VaryingsDefault i) : SV_Target
         {
             // 2D strip lut
-            float3 colorLinear = GetLutStripValue(UnityStereoTransformScreenSpaceTex(i.texcoord), _Lut2D_Params);
+            float3 colorLinear = GetLutStripValue(i.texcoordStereo, _Lut2D_Params);
             float3 graded = ColorGradeLDR(colorLinear);
             return float4(graded, 1.0);
         }