Fix S3237: NullReferenceException with arrow expression of interface member

sonaranalyzer-dotnet/src/SonarAnalyzer.CSharp/Rules/UseValueParameter.cs

@@ -57,7 +57,7 @@ protected override void Initialize(SonarAnalysisContext context)
 
                     var interfaceMember = c.SemanticModel.GetDeclaredSymbol(accessor).GetInterfaceMember();
                     if (interfaceMember != null &&
-                        accessor?.Body.Statements.Count == 0) // No need to check ExpressionBody, it can't be empty
+                        accessor.Body?.Statements.Count == 0) // No need to check ExpressionBody, it can't be empty
                     {
                         return;
                     }

sonaranalyzer-dotnet/tests/SonarAnalyzer.UnitTest/TestCases/UseValueParameter.cs

@@ -121,6 +121,24 @@ public override event EventHandler Bar3
         }
     }
 
+    // implement interface using arrow syntax
+    public class Baz : IFoo
+    {
+        private int foo1;
+
+        public int Foo1
+        {
+            get => 42;
+            set => foo1 = 0; // Noncompliant
+        }
+
+        public event EventHandler Bar3
+        {
+            add => throw new Exception();
+            remove => throw new Exception();
+        }
+    }
+
     public class NewSyntax
     {
         public int ReadonlyGetter { get; }