get rid of some warnings (all false positives)

get rid of some warnings (all false positives)

Assets/ScriptableRenderPipeline/HDRenderPipeline/Lighting/TilePass/Resources/lightlistbuild-bigtile.compute

 	// sort lights
 	SORTLIST(lightsListLDS, iNrCoarseLights, MAX_NR_BIGTILE_LIGHTS_PLUSONE, t, NR_THREADS);
 
-	lightOffs = 0;
+	if(t==0) lightOffs = 0;
 	GroupMemoryBarrierWithGroupSync();
     int i;
 	for(i=t; i<iNrCoarseLights; i+=NR_THREADS) if((int)lightsListLDS[i]<g_iNrVisibLights) InterlockedAdd(lightOffs, 1);

Assets/ScriptableRenderPipeline/HDRenderPipeline/Lighting/TilePass/Resources/lightlistbuild-clustered.compute

 	}
 
 #ifdef ENABLE_DEPTH_TEXTURE_BACKPLANE
-	g_logBaseBuffer[tileIDX.y*nrTilesX + tileIDX.x] = suggestedBase;
+	if(threadID==0) g_logBaseBuffer[tileIDX.y*nrTilesX + tileIDX.x] = suggestedBase;
 #endif
 }
 

Assets/ScriptableRenderPipeline/HDRenderPipeline/Lighting/TilePass/Resources/lightlistbuild.compute

 #ifdef PERFORM_SPHERICAL_INTERSECTION_TESTS
 int SphericalIntersectionTests(uint threadID, int iNrCoarseLights, float2 screenCoordinate)
 {
-	lightOffsSph = 0;
+	if(threadID==0) lightOffsSph = 0;
 
 	// make a copy of coarseList in prunedList.
     int l;

Assets/ScriptableRenderPipeline/fptl/lightlistbuild-bigtile.compute

 	// sort lights
 	SORTLIST(lightsListLDS, iNrCoarseLights, MAX_NR_BIGTILE_LIGHTS_PLUSONE, t, NR_THREADS);
 
-	lightOffs = 0;
+	if(t==0) lightOffs = 0;
 	GroupMemoryBarrierWithGroupSync();
 	for(int i=t; i<iNrCoarseLights; i+=NR_THREADS) if(lightsListLDS[i]<g_iNrVisibLights) InterlockedAdd(lightOffs, 1);
 	GroupMemoryBarrierWithGroupSync();

Assets/ScriptableRenderPipeline/fptl/lightlistbuild-clustered.compute

 	}
 
 #ifdef ENABLE_DEPTH_TEXTURE_BACKPLANE
-	g_logBaseBuffer[tileIDX.y*nrTilesX + tileIDX.x] = suggestedBase;
+	if(threadID==0) g_logBaseBuffer[tileIDX.y*nrTilesX + tileIDX.x] = suggestedBase;
 #endif
 }
 

Assets/ScriptableRenderPipeline/fptl/lightlistbuild.compute

 #ifdef PERFORM_SPHERICAL_INTERSECTION_TESTS
 int SphericalIntersectionTests(uint threadID, int iNrCoarseLights, float2 screenCoordinate)
 {
-	lightOffsSph = 0;
+	if(threadID==0) lightOffsSph = 0;
 
 	// make a copy of coarseList in prunedList.
 	for(int l=threadID; l<iNrCoarseLights; l+=NR_THREADS)