Fixed HDRP when decal are disabled (issue caused by RTHandle PR)

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDRenderPipeline.cs

 
                 m_SSSBufferManager.PushGlobalParams(cmd, sssParameters, m_FrameSettings);
 
-                m_DbufferManager.PushGlobalParams(cmd);
+                m_DbufferManager.PushGlobalParams(cmd, m_FrameSettings);
 
                 m_VolumetricLightingModule.PushGlobalParams(hdCamera, cmd);
             }

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Material/Decal/DBufferManager.cs

 using UnityEngine.Rendering;
+using UnityEngine.Rendering.PostProcessing;
 
 namespace UnityEngine.Experimental.Rendering.HDPipeline
 {
             cmd.ClearRandomWriteTargets();
         }
 
-        public void PushGlobalParams(CommandBuffer cmd)
+        public void PushGlobalParams(CommandBuffer cmd, FrameSettings frameSettings)
-            cmd.SetGlobalInt(HDShaderIDs._EnableDBuffer, vsibleDecalCount > 0 ? 1 : 0);
-            BindBufferAsTextures(cmd);
+            if (frameSettings.enableDBuffer)
+            {
+                cmd.SetGlobalInt(HDShaderIDs._EnableDBuffer, vsibleDecalCount > 0 ? 1 : 0);
+                BindBufferAsTextures(cmd);
+            }
+            else
+            {
+                cmd.SetGlobalInt(HDShaderIDs._EnableDBuffer, 0);
+                // We still bind black textures to make sure that something is bound (can be a problem on some platforms)
+                for (int i = 0; i < m_BufferCount; ++i)
+                {
+                    cmd.SetGlobalTexture(m_TextureShaderIDs[i], RuntimeUtilities.blackTexture);
+                }
+            }
         }
     }
 }