fix: removes useless condition for null check

Signed-off-by: Vincent Biret <[email protected]>

Author: baywet

src/Microsoft.OpenApi/Writers/OpenApiWriterAnyExtensions.cs

@@ -111,10 +111,7 @@ private static void WriteObject(this IOpenApiWriter writer, JsonObject entity)
 
         private static void WritePrimitive(this IOpenApiWriter writer, JsonNode primitive)
         {
-            if (writer == null)
-            {
-                Utils.CheckArgumentNull(writer);
-            }
+            Utils.CheckArgumentNull(writer);
 
             var valueKind = primitive.GetValueKind();