Merge pull request #1135 from Unity-Technologies/Fix-up-layered-lit-materials-with-a-subsurface-mask-map

Fix up layered lit materials with a subsurface mask map

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/LayeredLit/LayeredLitData.hlsl

 #endif
 
 #if defined(_SUBSURFACE_MASK_MAP0)
-#define _SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap0
+#define SAMPLER_SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap0
-#define _SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap1
+#define SAMPLER_SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap1
-#define _SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap2
+#define SAMPLER_SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap2
-#define _SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap3
+#define SAMPLER_SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap3
 #endif
 
 #if defined(_THICKNESSMAP0)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitData.hlsl

 #define SAMPLER_MASKMAP_IDX sampler_MaskMap
 #define SAMPLER_HEIGHTMAP_IDX sampler_HeightMap
 
-#define SAMPLER_SUBSURFACE_MASKMAP_IDX sampler_SubsurfaceMaskMap
+#define SAMPLER_SUBSURFACE_MASK_MAP_IDX sampler_SubsurfaceMaskMap
 #define SAMPLER_THICKNESSMAP_IDX sampler_ThicknessMap
 
 // include LitDataIndividualLayer to define GetSurfaceData

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Lit/LitDataIndividualLayer.hlsl

     surfaceData.subsurfaceMask = ADD_IDX(_SubsurfaceMask);
 
 #ifdef _SUBSURFACE_MASK_MAP_IDX
-    surfaceData.subsurfaceMask *= SAMPLE_UVMAPPING_TEXTURE2D(ADD_IDX(_SubsurfaceMaskMap), SAMPLER_SUBSURFACE_MASKMAP_IDX, ADD_IDX(layerTexCoord.base)).r;
+    surfaceData.subsurfaceMask *= SAMPLE_UVMAPPING_TEXTURE2D(ADD_IDX(_SubsurfaceMaskMap), SAMPLER_SUBSURFACE_MASK_MAP_IDX, ADD_IDX(layerTexCoord.base)).r;
 #endif
 
 #ifdef _THICKNESSMAP_IDX