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/kvm_websocket.hpp b/include/kvm_websocket.hpp
index f83c95b..df50778 100644
--- a/include/kvm_websocket.hpp
+++ b/include/kvm_websocket.hpp
@@ -162,7 +162,7 @@
         .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 (sessions.size() == maxSessions)
@@ -173,10 +173,11 @@
 
             sessions[&conn] = std::make_unique<KvmSession>(conn);
         })
-        .onclose([](crow::websocket::Connection& conn,
-                    const std::string& reason) { sessions.erase(&conn); })
+        .onclose([](crow::websocket::Connection& conn, const std::string&) {
+            sessions.erase(&conn);
+        })
         .onmessage([](crow::websocket::Connection& conn,
-                      const std::string& data, bool is_binary) {
+                      const std::string& data, bool) {
             if (sessions[&conn])
             {
                 sessions[&conn]->onMessage(data);