fix warnings

com.unity.render-pipelines.high-definition/HDRP/Lighting/Reflection/HDAdditionalReflectionData.cs

         ReflectionProbe m_LegacyProbe;
         ReflectionProbe legacyProbe { get { return m_LegacyProbe ?? (m_LegacyProbe = GetComponent<ReflectionProbe>()); } }
 
+#pragma warning disable 649 //never assigned
         //data only kept for migration, to be removed in future version
         [SerializeField, System.Obsolete("influenceShape is deprecated, use influenceVolume parameters instead")]
         Shape influenceShape;
         Vector3 boxSideFadePositive = Vector3.one;
         [SerializeField, System.Obsolete("boxSideFadeNegative is deprecated, use influenceVolume parameters instead")]
         Vector3 boxSideFadeNegative = Vector3.one;
+#pragma warning restore 649 //never assigned
 
         bool needMigrateToHDProbeChild = false;
 

com.unity.render-pipelines.high-definition/HDRP/Lighting/Reflection/Volumes/InfluenceVolume.cs

         Shape m_Shape = Shape.Box;
         [SerializeField, FormerlySerializedAs("m_BoxBaseOffset")]
         Vector3 m_Offset;
+#pragma warning disable 649 //never assigned
+#pragma warning restore 649 //never assigned
 
         // Box
         [SerializeField, FormerlySerializedAs("m_BoxBaseSize")]