Enable unused variable warnings and resolve

This commit enables the "unused variables" warning in clang.  Throughout
this, it did point out several issues that would've been functional
bugs, so I think it was worthwhile.  It also cleaned up several unused
variable from old constructs that no longer exist.

Tested:
Built with clang.  Code no longer emits warnings.

Downloaded bmcweb to system and pulled up the webui, observed webui
loads and logs in properly.

Change-Id: I51505f4222cc147d6f2b87b14d7e2ac4a74cafa8
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/include/vm_websocket.hpp b/include/vm_websocket.hpp
index d07469e..da9a06f 100644
--- a/include/vm_websocket.hpp
+++ b/include/vm_websocket.hpp
@@ -160,7 +160,7 @@
         .privileges({"ConfigureComponents", "ConfigureManager"})
         .websocket()
         .onopen([](crow::websocket::Connection& conn,
-                   std::shared_ptr<bmcweb::AsyncResp> asyncResp) {
+                   std::shared_ptr<bmcweb::AsyncResp>) {
             BMCWEB_LOG_DEBUG << "Connection " << &conn << " opened";
 
             if (session != nullptr)
@@ -183,16 +183,21 @@
             handler = std::make_shared<Handler>(media, conn.get_io_context());
             handler->connect();
         })
-        .onclose(
-            [](crow::websocket::Connection& conn, const std::string& reason) {
-                session = nullptr;
-                handler->doClose();
-                handler->inputBuffer->clear();
-                handler->outputBuffer->clear();
-                handler.reset();
-            })
+        .onclose([](crow::websocket::Connection& conn,
+                    const std::string& /*reason*/) {
+            if (&conn != session)
+            {
+                return;
+            }
+
+            session = nullptr;
+            handler->doClose();
+            handler->inputBuffer->clear();
+            handler->outputBuffer->clear();
+            handler.reset();
+        })
         .onmessage([](crow::websocket::Connection& conn,
-                      const std::string& data, bool is_binary) {
+                      const std::string& data, bool) {
             if (data.length() > handler->inputBuffer->capacity())
             {
                 BMCWEB_LOG_ERROR << "Buffer overrun when writing "